RE: Compaq Portable 286 and Portable III - IDE drives?

[Tom Gardner via cctalk]

I'm pretty sure the Portable III used a Conner IDE disk drive, see
http://chmss.wikifoundry.com/page/Compaq%2FConner+CP341+IDE%2FATA+Drive
probably the CP344 but maybe the CP341 (there is some inconsistency in  the
literature)

However that was the first public IDE drive so it is not at all clear how
compatible the Compaq HBA/driver was with future versions of IDE/ATA, so if
I were you I would get early Conner IDE drives as replacements such as
models CP3024, CP3044, CP344, CP3104, CP3114 and CP3204 - all listed in the
1989 Disk/Trend as Conner PC-AT drives (i.e. IDE drives).

Tom

-Original Message-
From: Jules Richardson [mailto:jules.richardso...@gmail.com] 
Sent: Friday, March 03, 2017 12:52 PM
To: cctalk@classiccmp.org
Subject: Compaq Portable 286 and Portable III - IDE drives?


Just checking here, as someone told me that this is the case, but do the
Compaq Portable 286 and Portable III take stock 40-pin IDE hard drives? I
just wanted to make sure that they weren't expecting something that might be
a bit non-standard before I go trying to find modern replacements for a pair
of failing disks.

Assuming that an enormous modern(ish) drive is OK, are there any other
gotchas involved in configuration and formatting? Obviously I don't need a
partition bigger than a few tens of MB, but perhaps there are things to keep
in mind when fitting a drive that's most likely to be getting on for a
thousand times the capacity of the original.

cheers

Jules

Chip in first Apple AirPort WiFi

[Tom Gardner via cctalk]

Anyone know which Lucent semiconductor device or devices were used in the
first Apple AirPort, the Lucent board was " Lucent WaveLAN Silver PC Card"
but I'd like to know the devices used.

Tom

RE: The Name of the disk (Was: Disk imaging with IMD - question

[Tom Gardner via cctalk]

Me too - great rant.
Thanks
Tom

-Original Message-
From: Mark J. Blair [mailto:n...@nf6x.net] 
Sent: Thursday, August 10, 2017 9:56 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: The Name of the disk (Was: Disk imaging with IMD - question


> On Aug 9, 2017, at 12:08, Fred Cisin via cctalk 
wrote:
> 
> 
[...]
> 


I'm keeping your rant as reference material. Thanks!

The Tandy Portable Disk Drive (TPDD) for the Model 100 series is one of the
odd-ball "rare" configurations: 3.5", 40 track (later, 80 track on the
TPDD2), single sided, two (!) sectors of 1280 bytes each per track. Disk
capacities are nominally called "100k" or "200k". I have not yet tried
examining a TPDD disk on some sort of imaging setup to get insight into its
low-level format, but that's on my growing "one of these days" list. The
drives had internal controllers and brains, and connected to the computer
over an RS-232 interface.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

RE: 5.24-inch FDD invention [was RE: Diskette size]

[Tom Gardner via cctalk]

Jobs had nothing to do with the invention of the 5.25" FDD: 

The original impetus for a smaller less expensive FD came from Lanier via Jimmy 
Adkisson in mid 1975

By early 1976 the Shugart Associate's engineers were working on a medium and 
device based upon the size of the cassette tape drive

Circa early Feb 1976 Don Massaro and Adkisson visited Wang Labs and Dr. Wang 
accepted the concept.  This was the key acceptance since at the time Wang was 
the dominant OEM buyer of FDs.

Feb 22-25, 1976, George Sollman did an East Coast market survey of potential 
minifloppy users.  The specs presented at that point were essentially the same 
as the SA400 (I have a copy of the Sollman presentation)

Development test was in June and completed in July; evaluation units went to 
Wang in August and production units shipped in Sept 1976

A nine month schedule in part due to the use of the 8-inch head which in turn 
limited the unit to 35 tracks.  The industry ultimately adopted 40 tracks which 
I think was pioneered by Tandon.

Apple was founded in April 1976 and incorporated in January 1977; the Apple ][ 
was announced in April 1977 without an FD.  The Disk II did not go on sale 
until 1978 - two plus years after the SA400 objectives were final.  Clearly 
Jobs had nothing to do with the invention of the 5.25-inch 

Jobs probably did get his $100 FD by buying a naked drive and allowing Wozniak 
to do the electronics.  Some observers think the Wozniak design was an 
innovation and some think it was a disaster, but that is another discussion :-)

Tom

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Thursday, July 20, 2017 11:47 PM
To: Steve Malikoff via cctalk
Subject: Re: Diskette size

On 07/20/2017 10:42 PM, Steve Malikoff via cctalk wrote:
> Eric said:
>> I think Shugart settled on 5.25" for the size of a minifloppy at 
>> least a year, and more likely two years, before Steve Jobs would have 
>> visited. I don't have proof, but SA400 public intro was in 1976, and 
>> they probably took more than a year of development to get to that point.
> 
> For interest there's an SA-400 announcement article on page 86 of BYTE, 
> December 1976:
> https://archive.org/details/byte-magazine-1976-12

Others followed quickly.  I think Micropolis was sampling their 100 tpi drive 
in 1977 according to my memory.  The first ones were pretty buggy, with an ugly 
tendency to wrinkle the annulus of the diskette.
Apparently they weren't the only ones, as Dysan started to add a reinforcing 
ring to their 5.25 floppies.  Micropolis eventually solved the problem by 
detecting when the drive door was being closed and running the spindle motor 
until the door was fully closed.

--Chuck

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

Sorry for the typo, I typed 6 where I should have typed 9, as in 1969 when I 
meant 1989.  But my 20 years typo doesn’t change a thing. L

 

Chuck’s old Wren III supports the point. Wren III’s began shipping in the late 
80s and so his recollection (if correct) that  ‘ the interface is called "ATA", 
with no mention of "IDE" ’ suggests at least Imprimis wasn’t using IDE at that 
time but was using ATA.

 

Porter’s Disk/Trend doesn’t mention IDE until its 1992 edition; its 1988 
edition identifies 14 manufacturers of drives having what he called a “PC AT” 
interface.   As I said, I think the term IDE came into public usage from WD in 
1991 or 1992.  

 

I don’t think any digging is necessary but if I had to I suppose I could go to 
the Computer History Museum and pull up Porter’s files for the early ATA drive 
manufacturers and see what term their literature uses.

 

Tom

 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Sunday, October 01, 2017 12:59 PM
To: Tom Gardner via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

 

On 10/01/2017 12:46 PM, Tom Gardner via cctalk wrote:

> I've looked for but cannot find any WD or Compaq documents publically 

> using IDE to describe what ultimately issued as ATA-1.  My search 

> included various Compaq maintenance manuals.  The earliest public use 

> of ATA and AT attachment that I can find is March 1989 [1969] at the CAM 

> committee draft standard long before IDE was linuga franca for these 

> drives.  The earliest public disclosure of the interface that I can 

> find is revision IV to the Conner CP3022 specification dated Feb 1988; 

> it doesn t name the interface other than in terms of  task file 

> emulation.   It is likely that such documents existed from Conner 

> prior to Feb 1988, perhaps as early as shipping the CP344 in 4Q86.

> My point is the interface was public before it was named.

> 

> My recollection (possibly flawed) is WD tried to have the responsible 

> committee change the name to IDE and failed.

> 

> I do have a confidential WD document from 1985 [1965] which does use the term 

> IDE for "Integrated Drive Electronics" referring to their chips, a 

> drive built with these chips was called an "Integrated Drive" or an 

> ID.

> 

> The earliest advertisements and specifications for what we would now 

> call ATA-1 drives from Conner, MiniScribe and Quantum did not use 

> either the term IDE or ATA.  I have a list of terms used if anyone 

> cares.

> 

> As best I can tell WD began publically using the term IDE for its 

> drives sometime around 1990 - if anyone can find a public usage prior 

> to March 1989 of IDE to describe what became ATA-1  I'd really like to 

> see it.

> 

> The CAM and ANSI committees have since March 1989 [1969] defined ATA == AT 

> Attachment and NEVER used "Advanced Technology" as an acronym for AT 

> in any standard or draft including the one cited below!  There are

> 134 possible definitions < <https://www.acronymfinder.com/AT.html> 
> https://www.acronymfinder.com/AT.html>  of 

>  AT,  including for example,  Appropriate Technology sure the 

> connection to IBM s PC/AT  is obvious, but the authors, editors and 

> reviewers of the standards never meant it to mean  Advanced 

> Technology  so I suggest we respect their definition and not leap to 

> an obvious but incorrect conclusion.

 

Tom, I think your dates are about 20 years early.

 

I do have an old CDC Wren III half-height manual where the interface is called 
"ATA", with no mention of "IDE".  Even then, we still referred to

the drives as "IDE".   That term had to come from somewhere.

 

So perhaps some digging is in order.

 

--Chuck

 

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

Nice find but still later than Mar 1989.

 

Since Compuadd didn’t make drives it does raise the question of whose drives 
were in there.

 

Thanks

 

Tom

 

From: wrco...@wrcooke.net [mailto:wrco...@wrcooke.net] 
Sent: Monday, October 02, 2017 5:48 PM
To: Tom Gardner; General Discussion: On-Topic and Off-Topic Posts
Subject: RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

 

>From the Oct 2 1989 Infoworld (here 
>https://books.google.com/books?id=vTAEMBAJ 
><https://books.google.com/books?id=vTAEMBAJ=PT6=PT6=compaq+brochure=bl=OFrm0z4OIF=ngg5Ojsj-ABUs7YeAEQ48BegRUg=en=X=0ahUKEwjKsqy9nNPWAhXFz4MKHSAiCkIQ6AEIVjAM#v=onepage=ide=false>
> 
>=PT6=PT6=compaq+brochure=bl=OFrm0z4OIF=ngg5Ojsj-ABUs7YeAEQ48BegRUg=en=X=0ahUKEwjKsqy9nNPWAhXFz4MKHSAiCkIQ6AEIVjAM#v=onepage=ide=false)

 

"All five Compuadd systems include an ide hard drive and floppy disk 
controllers"

 

Will

 

On October 2, 2017 at 8:04 PM Tom Gardner via cctalk <cctalk@classiccmp.org> 
wrote:

Unfortunately there is no documentation to support Pete's recollection - if 
there is any I would like to see it.

For example:

· WD's Fall 1988 Corporate Product Overview does not use the terms IDE, 
Intelligent d..., or Integrated d... Similarly, WD's October 23, 1989 press 
release " WESTERN DIGITAL

ANNOUNCES VOLUME SHIPMENT OF ITS NEW AT-COMPATIBLE, 3.5-INCH INTELLIGENT 
DRIVES," does not use the acronym IDE or any of its meanings.

· Conner as late as 1990 was not using the acronym IDE or any of its meanings 
in its product literature.

· The MiniScribe 1988 announcement of its 8000 series did not use the acronym 
IDE or any of its meanings

So if WD, Conner and possibly MiniScribe weren’t using the term in 1989 I have 
a hard time accepting it's common use that early.

But again if anyone has any documents dating IDE in the 1980s I’d love to see 
them

Tom

-Original Message-
From: Pete Turnbull [mailto:p...@dunnington.plus.com]
Sent: Monday, October 02, 2017 8:29 AM
To: Tom Gardner via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

On 01/10/2017 20:46, Tom Gardner via cctalk wrote:

As best I can tell WD began publically using the term IDE for its

drives sometime around 1990

Nope. I recall conversations with a small-scale developer in the UK who was 
creating addons and accessories for the company I worked for (Acorn

Computers) in 1987-1988, and he was touting IDE as best improvement (because 
simpler and cheaper to interface) on ST506/ST412 interface drives for the hard 
drive upgrades he was about to market. I recall having to ask what IDE stood 
for, at the time. So it must have been in common use, at least amongst 
developers, by then. By 1989 there were more people using "IDE" - by that name 
- than anything else in the markets I was involved in.

--

Pete

Pete Turnbull

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

Unfortunately there is no documentation to support Pete's recollection - if 
there is any I would like to see it.

 

For example:

· WD's Fall 1988 Corporate Product Overview does not use the terms IDE, 
Intelligent d..., or Integrated d...  Similarly, WD's October 23, 1989 press 
release " WESTERN DIGITAL 

ANNOUNCES VOLUME SHIPMENT OF ITS NEW AT-COMPATIBLE, 3.5-INCH INTELLIGENT 
DRIVES,"  does not use the acronym IDE or any of its meanings.

· Conner as late as 1990 was not using the acronym IDE or any of its 
meanings in its product literature.

· The MiniScribe 1988 announcement of its 8000 series did not use the 
acronym IDE or any of its meanings

 

So if WD, Conner and possibly MiniScribe weren’t using the term in 1989 I have 
a hard time accepting it's common use that early.

 

But again if anyone has any documents dating IDE in the 1980s I’d love to see 
them

 

Tom

 

-Original Message-
From: Pete Turnbull [mailto:p...@dunnington.plus.com] 
Sent: Monday, October 02, 2017 8:29 AM
To: Tom Gardner via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

 

On 01/10/2017 20:46, Tom Gardner via cctalk wrote:

 

> As best I can tell WD began publically using the term IDE for its 

> drives sometime around 1990

 

Nope.  I recall conversations with a small-scale developer in the UK who was 
creating addons and accessories for the company I worked for (Acorn

Computers) in 1987-1988, and he was touting IDE as best improvement (because 
simpler and cheaper to interface) on ST506/ST412 interface drives for the hard 
drive upgrades he was about to market.  I recall having to ask what IDE stood 
for, at the time.  So it must have been in common use, at least amongst 
developers, by then.  By 1989 there were more people using "IDE" - by that name 
- than anything else in the markets I was involved in.

 

--

Pete

Pete Turnbull

 

The origin of SCSI [WAS:RE: The origin of the phrases ATA and IDE ]

[Tom Gardner via cctalk]

I suspect this might start another discussion, but as I understand it Apple had 
little to do with the evolution of SASI into SCSI.
Shugart Associates published SASI in 1981 and took it to ANSI in 1982 where 
they renamed it SCSI to avoid using a vendors name.  

To quote from the draft SCSI 1 standard

" A commercial small system
parallel bus, the Shugart Associates System Interface (SASI), generally met
the small system requirements for a device-independent peripheral or system
bus and had enjoyed significant market success. It was offered to X3T9.2 as
the basis for a standard. X3T9.2 chose the name Small Computer System
Interface (SCSI) for that standard and began work at its April 1982 meeting.

The present SCSI dpANS is a formalization and extension of the SASI. Many
existing SASI devices are SCSI compatible.

Since April 1982, X3T9.2 has held plenary sessions, at two month intervals,
plus numerous informal working meetings. The original SASI has been extended
in a number of ways"

I was at Shugart at that time and to the best of my recollection Apple was not 
a driver of the ANSI activity.
The Macintosh shipped in January 1984 well after the ANSI SCSI work started and 
its major distinguishing feature was the non-standard connector

Tom

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Wednesday, October 04, 2017 1:46 PM
To: Fred Cisin via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]



As an aside, I picked up a 1986 Wren II full-height manual that
discussed the drive and its various interfaces.   Sadly, IDE isn't one,
but SCSI is referred to as "SASI Subset"; i.e. "SCSI (SASI subset)"

That concurs with my observation that SCSI was initially an Apple convention.  
I can recall conversations about SASI vs. Apple SCSI.

--Chuck

RE: Reviving ancient MFM drives (was Re: formatting MFM drives on a IBM PC)

[Tom Gardner via cctalk]

Old 10 and 20 MB  MFM drives are most likely open loop positioning systems 
which are highly vulnerable to off track due to thermal changes and stiction.  
They also could have flying height problems due to contamination on the slider. 
 These failure modes can manifest themselves a slow soft problems such as you 
are describing

One thing I would do is format them only after they are warmed up and well 
exercised and then I would never turn them off.  If I did turn them off then I 
would have a batch file do a bunch of seeks for a minute or so during the boot 
and if I were really clever find a way to do a seek  every 5 minutes or so.

Tom

-Original Message-
From: Adrian Stoness [mailto:tdk.kni...@gmail.com] 
Sent: Thursday, September 28, 2017 9:41 AM
To: Geoffrey Oltmans; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Reviving ancient MFM drives (was Re: formatting MFM drives on a 
IBM PC)

prolly a failing ic of some sort?


On Thu, Sep 28, 2017 at 11:21 AM, Geoffrey Oltmans via cctalk < 
cctalk@classiccmp.org> wrote:

> On Thu, Sep 28, 2017 at 11:17 AM, Al Kossow via cctalk < 
> cctalk@classiccmp.org> wrote:
>
> >
> >
> > On 9/28/17 7:38 AM, Mike Stein via cctalk wrote:
> >
> > > What is it that usually fails when the drive can't read the servo info?
> > The data on the platter, or?
> >
> > I've never dug that far into it beyond fiddling with Micropolis 
> > trying to mechanically get it to find the servo tracks and calibrate 
> > to track 0.
> >
> > One of the problems is schematics and documentation on the servo 
> > systems are extremely difficult to get. The little that is on 
> > bitsavers is all I've come up with in 25 years of searching and 
> > there is practically nothing useful elsewhere on the web about 
> > fixing servos in old 5" disks.
> >
> > It could be heads, media, positioners, component aging in the analog 
> > section, etc etc..
> >
> >
> >
> >
>
> Speaking of I've got a couple of old MFM drives (10 and 20 MB of a 
> variety whose name and model #'s escape me, I wanna say Tandon, but 
> not sure). They seem to work fine when I initially format and 
> partition, but as they run for a while, they get more and more 
> unreliable. It seems to be a function of how long they've been running 
> for rather than a predictable pattern of bad tracks sectors? Are there 
> any good sources of troubleshooting info at the controller level for these 
> old drives?
>

RE: formatting MFM drives on a IBM PC

[Tom Gardner via cctalk]

I think Chuck has it backwards, AT Attachment as defined by the ANSI
committee publically predates IDE.  Although IDE was used internally at WD
it did not surface publically until well after the ANSI committee adopted AT
Attachment, abbreviated ATA.  The AT in AT Attachment or ATA has never stood
for "Advanced Technology" although many presume so.

A (P)ATA drive never directly connected to an AT bus, nor for that matter
any other bus but always required some form of adapter, albeit very simple
in the case of the 5170 type bus.  

The AT Attachment compatibility is with the Task File register set which can
be sent over any interface parallel, serial, carrier pigeon, whatever.  A
SATA drive could be connected to a 5170 with an 5170 bus to SATA bridge or
more like a PATA to SATA bridge (with a  PATA HBA in the 5170) - PATA to
SATA bridges did exist and u might find one on eBay.  Booting would be a
problem and so would capacity but it should talk.

So Serial ATA makes sense to me

Tom

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Thursday, September 28, 2017 5:37 PM
To: cctalk@classiccmp.org
Subject: Re: formatting MFM drives on a IBM PC

On 09/28/2017 05:12 PM, Jules Richardson via cctalk wrote:
> On 09/27/2017 09:59 AM, Ethan via cctalk wrote:
>> The idea of IDE, as my understanding, is the controller that existed 
>> as an ISA card was moved onto the actual drive, and then what became 
>> the controller was mostly just extending the ISA bus over to the 
>> drive.
> 
> I actually have an IDE "controller" somewhere which is just a tiny PCB 
> with an ISA connector on one side and a 40 pin IDE connector on the 
> other, along with a couple of ICs (presumably buffers/latches, but I 
> don't know without finding it).  It's somewhat unusual, given that IDE 
> ports were normally included as part of multi-I/O boards, or (a little
> later) often incorporated into the motherboard.

IDE used to be called "ATA" - "AT Attachment"; i.e. something tailored to
the PC AT (5170) 16-bit ISA bus.

What I find perplexing is the acronym "SATA" for "Serial ATA".  The name
would imply that a drive can be connected to a 5170, but I'm not aware of
any SATA adapters for the 5170 PC/AT.

--Chuck

The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

I've looked for but cannot find any WD or Compaq documents publically using IDE 
to describe what ultimately issued as ATA-1.  My search included various Compaq 
maintenance manuals.  The earliest public use of ATA and AT attachment that I 
can find is March 1969 at the CAM committee draft standard long before IDE was 
linuga franca for these drives.  The earliest public disclosure of the 
interface that I can find is revision IV to the Conner CP3022 specification 
dated Feb 1988; it doesn’t name the interface other than in terms of “task file 
emulation.”  It is likely that such documents existed from Conner prior to Feb 
1988, perhaps as early as shipping the CP344 in 4Q86.  My point is the 
interface was public before it was named.

 

My recollection (possibly flawed) is WD tried to have the responsible committee 
change the name to IDE and failed.

 

I do have a confidential WD document from 1965 which does use the term IDE for 
"Integrated Drive Electronics" referring to their chips, a drive built with 
these chips was called an "Integrated Drive" or an ID.  

 

The earliest advertisements and specifications for what we would now call ATA-1 
drives from Conner, MiniScribe and Quantum did not use either the term IDE or 
ATA.  I have a list of terms used if anyone cares.

 

As best I can tell WD began publically using the term IDE for its drives 
sometime around 1990 - if anyone can find a public usage prior to March 1989 of 
IDE to describe what became ATA-1  I'd really like to see it.

 

The CAM and ANSI committees have since March 1969 defined ATA == AT Attachment 
and NEVER used "Advanced Technology" as an acronym for AT in any standard or 
draft including the one cited below!  There are 134 possible definitions 
<https://www.acronymfinder.com/AT.html>  of “AT,” including for example, 
“Appropriate Technology”  – sure the connection to IBM’s PC/AT  is obvious, but 
the authors, editors and reviewers of the standards never meant it to mean 
“Advanced Technology” so I suggest we respect their definition and not leap to 
an obvious but incorrect conclusion.

 

Tom

 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Saturday, September 30, 2017 5:58 PM
To: Tom Gardner via cctalk
Subject: Re: formatting MFM drives on a IBM PC

 

On 09/30/2017 04:12 PM, Tom Gardner via cctalk wrote:

> I think Chuck has it backwards, AT Attachment as defined by the ANSI 

> committee publically predates IDE.  Although IDE was used internally 

> at WD it did not surface publically until well after the ANSI 

> committee adopted AT Attachment, abbreviated ATA.  The AT in AT 

> Attachment or ATA has never stood for "Advanced Technology" although many 
> presume so.

 

"IDE" was a Western Digital term for drives used in the Compaq PC,

dating from 1986.   I've probably got documents from about that time

talking about IDE, if I look.   Because of Compaq's introduction of the

thing early on, that's what we called it then.

 

The "ATA Standard" began its work in 1988 by the Common Access Method committee 
of ANSI X3T10 and eventually came out with a standard in 1994, but that was 
long after "IDE" was the lingua franca term for these drives.  The ANSI 
document:

 

 <https://ecse.rpi.edu/courses/S15/ECSE-4780/Labs/IDE/IDE_SPEC.PDF> 
https://ecse.rpi.edu/courses/S15/ECSE-4780/Labs/IDE/IDE_SPEC.PDF

 

In, you'll read:

 

"The application environment for the AT Attachment Interface is any computer 
which uses an AT Bus or 40-pin ATA interface. The PC AT Bus is a widely used 
and implemented interface for which a variety of peripherals have been 
manufactured.  As a means of reducing size and cost, a class of products has 
emerged which embed the controller functionality in the drive.  These new 
products utilize the AT Bus fixed disk interface protocol, and a subset of the 
AT bus.  Because of their compatibility with existing AT hardware and software 
this interface quickly became a de facto industry standard."

 

So, even ANSI X3 talks about the PC AT bus.  And yes, "AT", according to IBM, 
stands for "Advanced Technology"

 

Pretty much, all you need to connect an ATA-1 drive to the 5170 bus is a couple 
of transceivers and an address decoder.

 

--Chuck

 

RE: IBM 3330 Drive

[Tom Gardner via cctalk]

FWIW Paul Alan's Living Computer Museum has (or had) working PDP10's using 
DEC’s RP06's 

  which are very similar to a 3330-11 (they are Memorex 677's with a bolt on 
DEC controller).  They will not mount a 3330 disk pack (3336) but they should 
mount a 3336-11 disk pack and probably spin it up but DEC’s fixed sector size 
will be an issue.  I seem to recall u could format IBM 3336-11 packs into the 
DEC format so u might actually be able to scan a full track without reformatting

 

I know of no operational 3330 or PCM equivalents (e.g. Memorex 3670, ISS/Itel 
7330, etc); the Computer History Museum purports to have one, Catalog Number 
L2006.1.5  , but 
it might be a -11.  It probably would power up and u probably could get it to 
seek and read (u would need a simple controller) but getting access from the 
museum would be a challenge.

 

Good luck.

 

Regards

 

Tom

 

-Original Message-
From: AJ Palmgren [mailto:microtechd...@gmail.com] 
Sent: Sunday, August 27, 2017 9:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: IBM 3330 Drive

 

Does anyone here have good technical experience with, or even better ACCESS to, 
an IBM 3330 compatible hard drive unit?  (working or not).

 

I'm getting more daring with my projects to attempt to read ancient magnetic 
flux transitions off of things, and I might have an opportunity to read a disk 
pack for one of these beauties.

 

I'm certain there are MANY obstacles to overcome with what I'm suggesting, and 
depending on what might be available, I'll tackle those one at a time as I 
cross those bridges.  But for now, I'll just ask about the hardware.

 

-- 

 

Thanks,

AJ

  http://QICreader.com

  http://Point4iris.com

  http://MightyFrame.com

 

RE: IBM 3330 Drive

[Tom Gardner via cctalk]

In the absence of a marking I would expect this to be a -1.  See if u can find 
a 3336 model number.  If there is no dash, then it likely predates the -11

Take a look at the other side of the pack.  As I recall to prevent mis-mounts, 
there was a pin and socket arrangement in the -11 pack; a -1 top of spindle was 
small cylinder with a flat top, but the -11 top had a contour (raised socket?) 
that matched an inverse contour (pin) in the bottom of the pack (or maybe the 
other way around) so that it was impossible for -11 packs to be mounted on -1 
drives and vice versa.

I agree the label "Share1" means it is likely the CKD format.

I suspect the speckling in the light band is just surface variations and has 
nothing to do with wear.  Oxide disks were not very smooth when compared to 
today's metal film disks.

Tom

-Original Message-
From: AJ Palmgren [mailto:microtechd...@gmail.com] 
Sent: Friday, September 01, 2017 12:08 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: IBM 3330 Drive

For reference, here is a picture of the disk pack that I am wanting to read.

http://bit.ly/2etUg30

I know, I got a bit nervous too when I saw the guy just holding it out exposed 
like that.  Let's hope he put it back in the canister very carefully and 
quickly.

Can anybody guess the correct model of disk pack from this single picture and 
angle?  (Sorry, it's all I have to go on right now).

Thanks!
-AJ


On Mon, Aug 28, 2017 at 11:16 AM, Tom Gardner via cctalk < 
cctalk@classiccmp.org> wrote:

> FWIW Paul Alan's Living Computer Museum has (or had) working PDP10's 
> using DEC s RP06's 
> <http://opac.libraryworld.com/opac/catalog_edit.php?catalog_
> id=230824_doc=standard.php=43>  which are very similar 
> to a
> 3330-11 (they are Memorex 677's with a bolt on DEC controller).  They 
> will not mount a 3330 disk pack (3336) but they should mount a 3336-11 
> disk pack and probably spin it up but DEC s fixed sector size will be 
> an issue.  I seem to recall u could format IBM 3336-11 packs into the 
> DEC format so u might actually be able to scan a full track without 
> reformatting
>
>
>
> I know of no operational 3330 or PCM equivalents (e.g. Memorex 3670, 
> ISS/Itel 7330, etc); the Computer History Museum purports to have one, 
> Catalog Number L2006.1.5 <http://www.computerhistory.
> org/collections/catalog/L2006.1.5> , but it might be a -11.  It 
> probably would power up and u probably could get it to seek and read 
> (u would need a simple controller) but getting access from the museum would 
> be a challenge.
>
>
>
> Good luck.
>
>
>
> Regards
>
>
>
> Tom
>
>
>
> -Original Message-
> From: AJ Palmgren [mailto:microtechd...@gmail.com]
> Sent: Sunday, August 27, 2017 9:42 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: IBM 3330 Drive
>
>
>
> Does anyone here have good technical experience with, or even better 
> ACCESS to, an IBM 3330 compatible hard drive unit?  (working or not).
>
>
>
> I'm getting more daring with my projects to attempt to read ancient 
> magnetic flux transitions off of things, and I might have an 
> opportunity to read a disk pack for one of these beauties.
>
>
>
> I'm certain there are MANY obstacles to overcome with what I'm 
> suggesting, and depending on what might be available, I'll tackle 
> those one at a time as I cross those bridges.  But for now, I'll just ask 
> about the hardware.
>
>
>
> --
>
>
>
> Thanks,
>
> AJ
>
>  <http://QICreader.com> http://QICreader.com
>
>  <http://Point4iris.com> http://Point4iris.com
>
>  <http://MightyFrame.com> http://MightyFrame.com
>
>
>
>


-- 

Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/

9/14 Panel discussion - Dialog: The Beginning of Online Search

[Tom Gardner via cctalk]

The IEEE Silicon Valley Technical History Committee is sponsoring a panel
discussion, "Dialog: The Beginning of Online Search" featuring Roger Summit
the founder of Dialog along with ex-employees and users.

 

Register at: https://scvhist20170914.eventbrite.com/ 

 

More information at:  http://sites.ieee.org/sv-techhist/?p=662

 

Tom

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

WD acquired the Tandon drive business in 1988 so it was both a drive maker
and a chip supplier to other drive makers.

WD used the term "Integrated Drive Electronics" internally as early as June
23, 1985 on proprietary business plans (I have copies) but the target
"Intelligent Drive" interfaces are SCSI and "host level" without detail so I
don't think this counts as IDE in the sense of ATA.  My recollection is they
were then thinking more along the lines of direct connection to the host bus
- like Hardcard did.

Hallam speaking as a WD employee did not use IDE in his October 1986 Buscon
presentation where he disclosed direct connection to AT bus extension with
40 pin connector.  

An early WD (second?)  "intelligent" drive was announced in a September 23,
1989 press release as, "WESTERN DIGITAL ANNOUNCES VOLUME SHIPMENT OF ITS NEW
AT-COMPATIBLE, 3.5-INCH INTELLIGENT DRIVES" and "WD93024-A and WD93044-A, a
pair of AT-compatible, 3.5-inch, intelligent disk drives."  It did not use
the term IDE.  I looked for a product spec on line but did not find any.
Photos of these early WD intelligent drives either show no interface
definition or use the terms "PC XT" or "PC AT".

My recollection is that WD was indeed the leading proponent of "IDE" but I
can't find usage by them in 1989.

Tom



-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Wednesday, October 04, 2017 6:32 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM
drives on a IBM PC]

On Wed, 4 Oct 2017, Chuck Guzis via cctalk wrote:
> Why on earth would WD have anything to do with it?  They supplied the 
> controller, but not the drives.  I used to have an early Maxtor ~50MB 
> 3.5" drive with bugs in the interface.  Nowhere did they give any nod to
WD.

I was thinking in terms of their wholesale marketing TO the drive companies.
When they wanted to peddle their chipset to Maxtor, etc. what materials did
they send?
I assumed that WD was the first to produce a controller chipset.
Or was WD even the maker of the controller chips on the drive?

You're right, though, that WD may be totally irrelevant.
Surely, it would not have been hard for any of the drive makers to start
making their own.


When did any of the drive makers start saying "IDE" on their drive spec 
sheets?  (I've already make my rant about them not putting any of the 
information on the drive that was necessary for end users to use the 
drive)

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM

[Tom Gardner via cctalk]

-Original Message-
From: Alan Perry [mailto:ape...@snowmoose.com] 
Sent: Tuesday, October 03, 2017 12:27 PM
To: cctalk@classiccmp.org
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM

 

 



I am continuing to investigate, but I think that IDE came first. I have found 
references that describe the Compaq/WD/CDC Wren II HH disk (which pre-dates the 
formation of the SCSI-2 CAM committee) as "IDE". Some of this reportedly comes 
from the people who did the work (years after the fact). However, I have yet to 
find period documents that include the term "IDE". I don't know if the people 
who did the work used the term at the time or were applying it after the fact.

 

Here are a couple documents that I used as starting points -

 

  
http://chmss.wikifoundry.com/page/Compaq%2FConner+CP341+IDE%2FATA+Drive 

 

 
http://web.archive.org/web/20081004160101/http://www.ata-atapi.com/histcam.html 
 

 

alan

I looked at Compaq maintenance documents for the pre-CAM drives and did not 
find any name for the interface we now call ATA.

 

Both “starting point” documents were written well after the fact and I can say 
for sure the Wikifoundry document applied the terms after the fact without any 
attempt at sequencing.  I knew Gene and I am pretty sure his article did not 
attempt to time sequence the terms.

 

Tom

 

 

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

Thanks for your  research which supports my point since all your cites postdate 
the April 1989 date of ATA usage by the CAM committee.

Remember this all started when someone (Fred?) posted that ATA followed IDE.

Regards,

Tom
-Original Message-
From: Pete Turnbull [mailto:p...@dunnington.plus.com] 
Sent: Tuesday, October 03, 2017 10:56 AM
To: cctalk@classiccmp.org
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

On 03/10/2017 01:04, Tom Gardner via cctalk wrote:
> Unfortunately there is no documentation to support Pete's recollection - if 
> there is any I would like to see it.

Well, actually, there is, though not for quite as early as I had those 
conversations.  The company I was referring to was HCCS Associates, and 
although I can't find a copyright date for their original software, I can find 
pictures of the interfaces, clearly labelled "IDE", and one version of the 
software, called "IDE Manager".  It's version 2.1, dated February 1990.  They 
used mostly, but not exclusively, Connor drives, by the way.
http://chrisacorns.computinghistory.org.uk/Software.html#H
http://chrisacorns.computinghistory.org.uk/32bit_UpgradesH2Z/HCCS_IDE_A3000.html

Another I can find is another company who made an interface for a slightly 
later machine from the same family, and one version does carry a date, also 
1990.
http://chrisacorns.computinghistory.org.uk/32bit_UpgradesH2Z/ICS_ideA.html

The Watford Electronics IDE interface (called WE-IDE) for the same series of 
machines was released about the same time.  The software is dated September 
1989.  They used Western Digital drives, amongst others.
http://chrisacorns.computinghistory.org.uk/Software.html#W

So there's clear proof that at least three companies in the UK were using the 
term IDE before (or at least by) 1990.  I never heard it called anything else 
in that timeframe.

> -Original Message-
> From: Pete Turnbull [mailto:p...@dunnington.plus.com]

> Nope.  I recall conversations with a small-scale developer in the UK 
> who was creating addons and accessories for the company I worked for 
> (Acorn
> Computers) in 1987-1988, and he was touting IDE

--
Pete
Pete Turnbull

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

Adam – thanks for the research, can I assume that the other ads u found were 
also CompuAdd clone ads?

 

CompuAdd is really interesting because it clearly predates the CAM meeting in 
early 1989.  Here is a quote from the March 9, 1989, CAM minutes

“Gene Milligan pointed out that there is some standardization activity being 
done by Conner and Miniscribe in the area of mechanical and electrical 
characteristics of the AT controller interface (with specific application to 
embedded AT controller interface disk drives)”

 

“Embedded AT Controller” in some form (even just “AT”) seems to be the term of 
the industry prior to “IDE” and “ATA”

 

I have some fairly complete files on disk drive companies and from the limited 
material I have it appears that neither Conner, nor MiniScribe, nor Quantum, 
nor Imprimis used “IDE” in any form in their advertisements and product 
literature until well after the CAM meeting.  Here are some examples:

YYY-MM   Company   Quote Source

1987-06  Conner   an embedded IBM PC/AT controller  
   CP342 announcement Press Release

1988-02  Conner   designed to operate on an IBM PC AT   
  CP3022 Product Spec

1989-03  Imprimis A choice of industry-standard interfaces — 
SCSI, ESDI, AT, ST506  OEM Product Catalog

1989-04  CAM Com. Definition - ATA (AT Attachment): 
ATA-1 rev 2

1989-09  Quantum   the new ProDrive products are available with 
embedded SCSI or AT-Bus controllers. ProDrive 120-210 
announcement PR

1989-10  Miniscribe ST412, XT, AT, SCSI , or SCSI Macintosh 
interface 1989 Product Guide

1989-10  PrairieTek  DRIVE W ITH EMBEDDED AT OR XT CONTROLLER   
  PT120 & PT240 data sheer

1989-11  Kalok   Full SCSI, PC/AT or PS/2 interface 
compatibility Octagon I Family

1990-07  Arealdrives with the SCSI or AT interface  

   EN article

Of course my files are not as complete as Porter’s so if this becomes important 
I might have to visit the CHM and check them out.

 

The question becomes whose drives were CompuAdd using?  BTW if you scan two 
pages on in the cited PC Magazine u will find CompuAdd offering add-on “HDDs” 
for the “IBM-ATs” and “IBM-XTs”  from MiniScribe and Seagate - at that time 
Seagate did not have an ATA (or IDE) drive so maybe CompuAdd’s drives weren’t 
ATA as we now know it.

 

In any event this discussion started with an assertion that IDE preceded ATA 
and so far the evidence suggests IDE was at best contemporaneous.

 

Tom

 

-Original Message-
From: Adam Sampson [mailto:a...@offog.org] 
Sent: Tuesday, October 03, 2017 12:57 PM
To: Tom Gardner via cctalk
Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM 
drives on a IBM PC]

 

Tom Gardner via cctalk < <mailto:cctalk@classiccmp.org> cctalk@classiccmp.org> 
writes:

 

> But again if anyone has any documents dating IDE in the 1980s I d love 

> to see them

 

Don't forget the Internet Archive's impressive collection of scanned magazines 
for questions like this! There are several references in 1989 in Infoworld and 
similar periodicals.

 

The earliest I could find from a quick search is this ad from CompuAdd 
Corporation in PC Magazine, December 27th 1988, listing PC clones with 
"Integrated Drive Electronics fixed disk drive interface" and "IDE fixed disk 
drive interface":

 <https://archive.org/stream/PC-Mag-1988-12-27#page/n227/mode/2up> 
https://archive.org/stream/PC-Mag-1988-12-27#page/n227/mode/2up

 

The ad in the 1988-11-15 issue doesn't mention IDE, so it looks like that's one 
of the first times CompuAdd thought it was useful for marketing...

 

Cheers,

 

-- 

Adam Sampson < <mailto:a...@offog.org> a...@offog.org> 
< <http://offog.org/> http://offog.org/>

 

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Tom Gardner via cctalk]

After reading all the input I updated the article at:

http://chmss.wikifoundry.com/page/Compaq%2FConner+CP341+IDE%2FATA+Drive 

where you will now find a picture of what is likely the first ATA drive, called 
“fixed disk drive with embedded controller” by Compaq J

 

You might note that the article was approved by the CHM Storage SIG wherein it 
states:

 

The major reasons that ATA has become the most successful disk drive interface 
are: 
   1.  Ease of integration: the emulation of the WD1003 controller 
implementation in the PC/AT allowed booting without BIOS modifications, 
initially up to 528MB and subsequently to 137GB, although there were a number 
of other barriers to increased capacity that also had to be overcome along the 
way [16]

1.  2.  Low host cost and complexity: by separating the WD1003 
functions from the host functions, the cost of the host adapter was reduced to 
the point where it could be integrated first on to the motherboard and then 
into the “Southbridge.”

2.  3.  Acceleration of technology advancement: Like SCSI and the other 
“intelligent” interfaces, this broke the “controller barrier” but IDE/ATA was 
the only one that also had the above two advantages, providing a significant 
reduction in time-to-market and enabling ATA to rapidly catch up to the high 
end areal density growth curve, where it became the disk capacity leader, with 
the lowest cost per GB.

 

FWIW, the “controller barrier” is the delay in drive market acceptance required 
to design a new controller for a new drive interface.  For SMD is was about two 
years.

 

tom

RE: Idle question: Color of tape coatings

[Tom Gardner via cctalk]

Hi:

The following answer comes from a retired IBM tape technologist:

The color of the coatings on a tape are dominated by the magnetic pigment (or 
the carbon used in back coats..which is black)..the earliest iron oxide 
coatings were based on the conversion of alpha-iron oxide which is a pale 
yellow and some what needle shaped (longer than wide) but non-magnetic to gamma 
iron oxide which is magnetic. The very early particles were not very 
homogeneous and were very highly aggregatedpoor conversion as the early 
particle were being produced by paint pigment manufactures as a specialty 
product in low volume. These were a yellow brown color..but by the 60's  gamma 
iron oxide of 250-300 Oe was commonly used in the magnetic layer coatings. 
These were typically brown to chocolate brown  (if they had some carbon black 
mixed in for surface conductivity (anti-static) which depending on the use as 
well as the manufacturer varied a lot i n surface finish (gloss) as well). This 
market was driven by audio primarily and dynamic range and analogue signal 
characteristics such wow & flutter were driving formulation and magnetic 
particle development. 

In the late 60-s and 70's new particles began to enter the market..Cobalt doped 
and later cobalt 'modified"  gamma iron oxide as well as chromium dioxide..and 
some very early explorations of iron metal particles and some exotic mixed 
metal crystals... The colors of the magnetic coatings based on more acicular 
gamma iron oxide made specifically for the recording market were now reddish 
brown , cobalt doped were a dark brown - to black, chromium dioxide is very 
black..remember during this period digital recording in both tapes and disks 
were now the growth areas driving new pigment development and drastically 
improved formulations driven by the need for improved durability, longevity and 
wear characteristics (drop outs (defects & debris), head wear and head/drive 
contamination being increasingly problematic)..in the 90's metal particle and 
BaFe pigments took over tape while disks moved to thin film magnetic layers.

As for reel materials and hub evolution..the initial reels were metal and 
expensive...plastic became normal in the 60's and beyond for the most part..but 
for master copies or sensitive archival reels..glass or metal were preferred... 
but changes in the  materials were driven by the higher tape speeds,tensions 
and demands for improved reliability and durability. Hubs in some drives  had 
to be conductive so had carbon black or metals added to them to improve the 
compressive strength and conductivity.  A lot of very innovative but subtle 
design features moved into tape reels/hubs specifically designed for various 
transports and industry demands. In addition lubrication and binder changes 
were common as the needs for the various products in audio, video and digital 
recording  advanced. 

Hope this helps..but if the interest is primarily in getting a useful detailed 
knowledge of a particular tape..color is pretty much useless..you need SEM/EDAX 
and GC/MS and a database of tape analyses to compare to in order to really 
begin..and then to really know the tape you need DMA/DMTA mechanical analysis, 
and AFM/MFM surface profiles.but to my knowledge only IBM had that data and 
I imagine it ..like so much of that knowledge learned from 1962-2008 is now 
gone.

Tom

 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Monday, November 20, 2017 10:35 PM
To: CCtalk
Subject: Idle question: Color of tape coatings

 

While working on some old (again!) half-inch tapes, I note that some of the 
very old ones have an oxide coating about the color of milk

chocolate.   Newer ones are anywhere from dark chocolate to black.

 

Reel construction is another aspect.  The really old ones tend to be all clear 
plastic, including the hub area.  Newer ones have either a black plastic 
reinforcement to the hub or employ an aluminum sleeve.

 

In most cases, the oldest of these is from around 1964, but probably older than 
that, as the only clues I have are dates placed by the tape librarian when a 
tape is put back into the pool or a label indicating when the tape was last 
recertified.

 

Was there a date after which *all* half-inch tape became the dark brown to 
nearly black in color?

 

--Chuck

 

RE: Looking for AMP / TE coaxial connectors - Memorex 651 drive

[Tom Gardner via cctalk]

It  is from the AMP M series connector family used in the data cable for the 
IBM 2311/2314 and PCM equivalents including double density like the ISS 715 
(RP03?).  So some of the parts strippers should have lots.  

Using coax at the FDD data rate was overkill so unless you want to preserve the 
connector for historical purposes u should be able to push out and then remove 
the pins and connect the wires to whatever connector suits u - flat cable 
connector for the control signal cable and whatever works for the three coaxes  
(coax to twisted pair should work).

Tom

-Original Message-
From: Mattis Lind [mailto:mattisl...@gmail.com] 
Sent: Monday, December 11, 2017 12:45 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Looking for AMP / TE coaxial connectors - Memorex 651 drive

Hello!

I am about to start with the project to archive disks from the Incoterm system.

This system makes use of the Memorex 651 drive which is somewhat odd. It has 64 
tracks,is hard sectored with 32 sectors and spins at 375 rpm.

But I do have the drive which hopefully still is working. However the interface 
connector is nothing like I seen on a floppy drive before.

https://i.imgur.com/TklddLP.jpg


It is a AMP 202515-1 housing. The mating 202516-1 which I need is still in 
production and available for purchase from Mouser. The small coaxial connectors 
on the other hand has a minimum order of 1000 units and costs 10 euros each...

https://www.mouser.se/ProductDetail/TE-Connectivity/201146-2/?qs=DuOyNqEZh0%252bSNT4sy6om8Q==

Does anyone know of a source selling something like three coaxial connectors 
like this at decent price?

Or maybe a suggestion for another connector that could be modified into fit 
somehow? Potentially using glue to fixate it.

Of course the last resort is to just solder some wires directly onto the drive 
PCB, but if there is a nice solution I try that first.

RE: eBay: MEMOREX 3693-2 & 3690-2 Disc Drive Mainframe IBM 3370-2 VINTAGE

[Tom Gardner via cctalk]

AFAIK these are rebadged Japanese (probably NPL) controller and drives 
compatible with the IBM 3370 series.  The 3693-2 is a controller bundled with 
two drives while the 3690-2 is just two drives, other than skins just like the 
two in the 3693.  They are FBA as opposed to CKD

They likely connected to integrated attachments on low end IBM systems and 
director class control units on the IBM mainframes.

I'm pretty sure Memorex never did a 3390 class subsystem

Tom

-Original Message-
From: Guy Sotomayor Jr [mailto:g...@shiresoft.com] 
Sent: Saturday, December 16, 2017 11:29 AM
To: P Gebhardt; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: eBay: MEMOREX 3693-2 & 3690-2 Disc Drive Mainframe IBM 3370-2 
VINTAGE


> On Dec 15, 2017, at 4:04 AM, P Gebhardt via cctalk  
> wrote:
> 
> 
> 
> 
>> eBay: MEMOREX 3693-2 & 3690-2 Disc Drive Mainframe IBM 3370-2 VINTAGE
>> 
>> No connection to the seller, but they mention it will be scrapped if no 
>> takers. $150 Buy it now.
>> https://www.ebay.com.au/itm/MEMOREX-3693-2-3690-2-Disc-Drive-Mainframe-IBM-3370-2-VINTAGE/272983151498
>> or eBay item number: 272983151498
>> 
>> Steve.
> I saw that one today, too! If it wouldn't be across the great pond, then I 
> would try to save these drives from being scrapped.It would be a real shame 
> if nobody could take them. This Memorex equipment is very rare to come 
> across. 
> 

I *really* want them and I�m within an hour (usually) of where they are.  The 
problem is that right now I�m on a business trip until the end of the month and 
he needs this gone prior to 12/31.  So I can�t get them unless a miracle 
happens.

TTFN - Guy

RE: Looking for AMP / TE coaxial connectors - Memorex 651 drive

[Tom Gardner via cctalk]

Personally I can’t recommend any company selling used parts stripped from 
surplus equipment but I recall several being discussed in this thread.

 

My recollection in the 2311 and 2314 class disk drives from IBM, Memorex, ISS 
(sold by Itel and Telex), Calcomp, CDC, Ampex, etc all used M series for both 
the data and control cables.  The data cables were hermaphroditic with  two or 
three coax connector receptacles and a number of sockets at each end mating to 
the corresponding connectors in the drive and controller.  So what u really 
want to find is a data cable from these very old drives (or at least one half 
of one) and strip out the sockets.

 

It maybe the 651 used the same connector block as the 2314 class data cables; I 
doubt if Memorex had the money to pay AMP for a custom block so they just used 
the connector block that was in their 2311/2314 line – IBM paid AMP for that 
block J

 

Good luck.

 

Tom

 

From: Mattis Lind [mailto:mattisl...@gmail.com] 
Sent: Tuesday, December 12, 2017 12:38 PM
To: Tom Gardner; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Looking for AMP / TE coaxial connectors - Memorex 651 drive

 

 

 

2017-12-12 20:35 GMT+01:00 Tom Gardner via cctalk <cctalk@classiccmp.org>:

It  is from the AMP M series connector family used in the data cable for the 
IBM 2311/2314 and PCM equivalents including double density like the ISS 715 
(RP03?).  So some of the parts strippers should have lots.

 

What parts strippers is this? Did these drives use coax connectors as well? If 
someone see a used M-series with coax connector please save it! I am very 
interested in used parts as well.

 


Using coax at the FDD data rate was overkill so unless you want to preserve the 
connector for historical purposes u should be able to push out and then remove 
the pins and connect the wires to whatever connector suits u - flat cable 
connector for the control signal cable and whatever works for the three coaxes  
(coax to twisted pair should work).

 

I don't want to replace the current connector since the mating connector in the 
drive controller needs it. I just want something proper if possible to use when 
dumping the disks. But I don't want to spend a fortune of course. If not 
possible I simply solder wires to the relevant points on the drive circuit 
board.

 

 

 

 


Tom

 

 

/Mattis 

RE: Can anyone identify what this board is/does?

[Tom Gardner via cctalk]

My understanding is that DZU made disk storage subsystems including both drives 
and control units and that many if not all into the 1980s were copies of IBM 
disk storage products.

The recollection is that IBM 2314 era SCU used a form of TROS where words were 
strips of film that punched a hole a one or a zero at each transformer (core) 
location to route the current around or through a core.  The 2841 may have had 
the same technology.  This could be done relatively easily in the field.

At Memorex they used wire rope as TROS for the same function as I think did 
other PCMs.  This was smaller and allowed faster clocks than film strips but 
was difficult but not impossible to field upgrade.  Next generation SCUs went 
to writable control store's loadable from FDD's.

So this might be a 2314 era TROS so its date could be early 70s given first PCM 
2314's SCUs didn't ship until the early 1970s so I have a hard time thinking 
the Russian system beat US capitalism :-)
But if they copied the 2841 and it used TROS then it could be late 60s

Tom

-Original Message-
From: Tony Aiuto [mailto:tony.ai...@gmail.com] 
Sent: Saturday, December 02, 2017 8:45 AM
To: Brent Hilpert; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Can anyone identify what this board is/does?

On Fri, Dec 1, 2017 at 11:05 PM, Brent Hilpert via cctalk < 
cctalk@classiccmp.org> wrote:

> On 2017-Dec-01, at 7:12 AM, Tony Aiuto via cctalk wrote:
>
> > https://www.ebay.com/itm/263005049078
> >
> > EBay listing for a "Soviet Magnetic Ferrite Core Memory Board". It 
> > looks like 20 something gigantic cores and a lot of diodes. I am 
> > guessing it is some kind of ROM, but it doesn't look like a rope 
> > memory. And maybe the cores are not cores at all, but some sort of 
> > inductor. I've not seen this before.
>
>
> That's very funny.
> It looks to be a core rope memory that hasn't been programmed.
>

I think that is the most likely case.


>
> Other organisations might be possible, but it looks like a 
> pulse-transformer type of core-rope, where the cores are just for 
> ordinary induction, not switching/memory cores.
>
> - the matrix of black what-look-to-be diodes would be 
> data-wire isolation diodes
>
> - the little brown 'stools' are wire routing posts
>
> - you can see the mulit-turn sense windings (bluish) already 
> present on the cores
>
> - above the cores are the sense amplifiers or 1st stage 
> thereof
>
> - there is one wire through all the cores, perhaps a test wire 
> for core and sense amp response
>
> Each data-wire would start at one of the solder pins in the pin matrix 
> on the left, weave through the cores to encode the data, turn back 
> 180, then 90 degrees around one of the stools to drop down and 
> terminate at the solder pin by an isolation diode.
>
> There would be another board for decoding the address to 1-of-x and 1-of-y.
>
> I didn't count precisely but it looks like it would be 256 words of 20 
> bits.
>
> That might be a date code of 6847 on a cap (or is it 6B47?), so 
> perhaps earlier than the listing-stated 1981.
>
> Actually, it kind of hints at it in the description: "With out 
> Firmware ROM wire (empty slots)"
>

Ah, you read the description. I just looked at the title and saw "with the 
firmware". My addled brain made the leap to a external firmware, which made no 
sense. "firmware ROM wire" would be a clear case for rope memory.

On Fri, Dec 1, 2017 at 11:32 PM, Charles Anthony  wrote:
>
> The last picture has "???-5". Some googling takes us to
> https://bg.wikipedia.org/wiki/%D0%94%D0%97%D0%A3
>
> "DZU is a factory in Stara Zagora , a major producer of magnetic disk 
> storage devices (hard drives and floppy disks) during the rise of 
> computer production in Bulgaria in the 1970s and 1980s, century. Today 
> it is part of VIDEOTON Holding ZRt., Hungary [1] ."
>
> The article says it was a disk drive factory, but maybe...
>
> -- Charles
>

Given the cleanliness of the board and other things the seller is offering, my 
guess now is that this NOS from the DZU plant.


Thanks, everyone.

RE: Tubbs fire consumed the collected archives of William Hewlett and David Packard

[Tom Gardner via cctalk]

Apparently some of Hewlett's papers went to Stanford
"Two new collections open for research: Helen and Newton Harrison & William 
Hewlett"
http://library.stanford.edu/blogs/special-collections-unbound/2016/04/two-new-collections-open-research-helen-and-newton
 

Tom

-Original Message-
From: Ed Sharpe [mailto:couryho...@aol.com] 
Sent: Sunday, October 29, 2017 8:19 PM
To: cctalk@classiccmp.org
Subject: Re: Tubbs fire consumed the collected archives of William Hewlett and 
David Packard

Karen Lewis felt Stanford  was the place they should go... 

ed#

Sent from AOL Mobile Mail

On Sunday, October 29, 2017 Steven M Jones via cctalk  
wrote:
General comment to several earlier replies re: Bitsavers-type efforts.

The tragedy here is not that some copies of uncommon but otherwise extant 
product documentation were lost. From the description, there were a large 
number of unique, individual documents created by significant historical 
figures. Fair bet that many of these didn't exist anywhere else. Certainly not 
if it included drafts of speeches and correspondence, as well as the final 
copy, etc.

A better question (not that it does any good to ask it now) is why this stuff 
wasn't in the hands of university conservators or similar. I love bitsavers and 
warchive.org, but this is a level beyond what they typically focus on. (And to 
be sure, CHM would have at least kept such artifacts safe even if they couldn't 
do anything with them for a few
years/decades.)

Sigh. And I don't really mean to criticize anybody at Keysight, humans are 
generally bad at recognizing and planning for this kind of contingency - and 
I'm probably worst than most...

--S.

RE: IBM junk

[Tom Gardner via cctalk]

What an incredible collection and thanks for taking the time to photograph
it.  It was great fun going thru the slides.  From the content my guess is u
were at least at some time at IBM SJ

I understand u have a collector for all of it, but if by chance he/she and
you have some original 3880 Storage Control manuals particularly for the
caching models (-11,13,21,23) I'd like copies if it can be arranged.  If
they could be mailed to me I will scan them and provide originals and scans
back to the owner.  Contact me off line if this can be arranged

It is disappointing about the CHM; although most of the materials are
duplicates of what they have I did see a few gems I suspect they don't have

Regards,

Tom

-Original Message-
From: cct...@emailtoilet.com [mailto:cct...@emailtoilet.com] 
Sent: Saturday, June 23, 2018 12:34 AM
To: cctalk@classiccmp.org
Subject: IBM junk

Collected stuff for over 10 years.  Moving from 2300 sq. ft. to 1400.  It
had to go. Praise the computer gods I found someone that wanted it all.

115 boxes of manuals and documents.
26 boxes of coffee mugs
73 703 boxes of stuff.
106 loose big items.

Filled the floor space of a 26' truck.

It can be viewed at http://www.ibmjunkman.com/junk/

Best viewed on a PC with decent speed connection.

Sample stuff: 360 Mod 20 panel, mod 30 panel, mod 65 panel, s/3 panel. Disk
pack and HDA up the ying yang.3850 data carts, 2321 data cell, 7340
Hypertape cartridge, a Russian equivalent, desktop chachki (tchotchke), 360
mod 70 desktop model used in 1964 World's Fair,  etc, etc.

Early 12-inch WORM disk drives and media

[Tom Gardner via cctalk]

I'm pulling together a timeline of optical computer data storage and having
fun with the early ones.  A copy of Rothchild's Optical Memory Report,  From
the early 80's would be appreciated - hardcopies are at the CHM so maybe
I'll have to drive over there

 

I'm told by a reliable source and am trying to confirm that Philips and
Toshiba were first  circa 1980 so can anyone identify and provide any
details about any 12-inch WORM disk drives and media that were shipped by
either around 1980.

 

FWIW the earliest WORM I can identify is the OSI Laserdrive 1200 which
shipped in 1983.  OSI was a joint venture of Philips and CDC and in turn a
successor to their earlier joint ventures, Optical Media Laboratory in
Holland and Optical Peripherals Laboratory in Colorado.  So the Laserdrive
might be a rebadged or enhanced version of the earlier Philips product.

 

I have no clue as to any early Toshiba WORM

 

FWIW,  in 1981 Matsushita demonstrated  of a 200 mm diameter WORM disk with
a capacity of 15,000 still pictures but this wasn't a data disk.  Not clear
when and if it shipped as a product.  [source:
http://www.wtec.org/loyola/opto/ad_matsu.htm ]

 

There is also an indication that Thompson CF also had an optical data
storage system circa 1981 but I can find nothing about it.

 

Any recollections and all literature would be appreciated.

 

Tom

 

 

 

 

 

 

 

 

 

RE: Maxtor full-height 5.25" drives of death

[Tom Gardner via cctalk]

XT2190 was first produced in 3Q 1984 and last produced in 1989 which gives 
yours a remarkable life span and well beyond the them at most 5 year warranty.
Be thankful they lasted this long.

Tom

-Original Message-
From: Ian Finder [mailto:ian.fin...@gmail.com] 
Sent: Wednesday, February 07, 2018 11:36 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Maxtor full-height 5.25" drives of death

XT2190s, XT1140s, some of the early ESDI disks...
I have 6 XT2190s at home, and maybe one of the damn things works.

Does anyone out here know, beyond speculation, what some of the common failure 
modes of these drives are? I'm not opposed to open-HDA surgery.

And I probably won't do anything.
But the question of WHY this line of drives in particular sucks so much has 
haunted me for some time...

- Ian

Honorable mention: CDC Sabre, Wren.

-- 
   Ian Finder
   (206) 395-MIPS
   ian.fin...@gmail.com

RE: Computer tape quantities in the 70's or 80's?

[Tom Gardner via cctalk]

Phister's
  numbers in Table II 1.27a Supplies

 


Line

Item

Figure

Units

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978


20

Total Tapes Shipped

M

0.085

0.227

0.544

0.825

1.37

2.25

2.97

3.2

4

5

5.7

4.7

4.5

6.6

9.4

9.9

9.7

10.1

10.7

11.2

tom

 

-Original Message-
From: Shoppa, Tim [mailto:tsho...@wmata.com] 
Sent: Monday, August 06, 2018 11:34 AM
To: 'cctalk@classiccmp.org'
Subject: Re: Computer tape quantities in the 70's or 80's?

 

Chuck writes:

> I'd probably start with the US Commerce Department.  In their 

> industrial report summaries, the product code is "36950 11"

> e.g.:    https://tinyurl.com/y8ks3mdd   for
1987-88

 

Wow, Chuck, that is fascinating info that I had no idea was so easily
accessed. Thank you! It looks like the tape production in the 80's was 30M
to 40M reels per year so my guess at 100M was high but not too far off.

 

I super like some of the product codes just on those pages. E.g. 35711 22 is
Analog Computers, and 35751 75 is Teleprinters under 20 characters per
second (e.g. Model 33's which saw a steep decline through the 1980's. I'm
guessing they would've peaked in the early 70's.).

 

Tim N3QE

 

First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

[Tom Gardner via cctalk]

Well it all depends upon what u mean by "first"

The Sony drive and cartridge were not compatible in many ways with what
became the physical, magnetic and electrical interface standards for the
3.5-inch drive and cartridge.  The standards came out of the "Microfloppy
Industry Committee" (Google it with quotes) organized by Shugart Corp.
Either Shugart or Tandon was the first to ship drives compatible to the
standard.  Tandon probably did the first such cartridge.

The original Sony drive and cartridge died out and Sony didn't come out with
a compatible set until well after Shugart and Tandon.  The early adopters of
the Sony design like HP then changed to the industry standard design.

Tom

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Wednesday, August 22, 2018 1:25 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Prototype IBM DemiDiskette drive

>> I just picked up a Model 350 on eBay, just because I'd never seen a 
>> Shugart sub 5" drive.
>> https://www.ebay.com/itm/Vintage-Sankyo-Shugart-Venture-Model-350-
>> Computer-Disk-Drive-/253708808435

On Wed, 22 Aug 2018, Ali via cctalk wrote:
> Interesting. I wonder if IBM was looking at those drives for use. The
seller (or more accurately the seller's father) used to work for IBM
Industrial services in Boca Raton.

Well, the SA300 (single sided version) were not the first 3.5" drives, but
they may have been the first 300 RPM ones with an SA400 interface. 
(The Sony 600RPM drives would require more changes)

The SA300 could be dropped into a 5150 (with only issues of mounting
brackets (Erector set) and power connector) and were supported by some OEM
versions of MS-DOS 2.11.  IBM public support of 3.5" began with PC-DOS 3.20.

RE: Prototype IBM DemiDiskette drive

[Tom Gardner via cctalk]

It was the SA200 a 2/3rds height (51 mm) 5¼-inch FDD at $118 in quantities of 
5,000 or more.  It was sold in 1982 but got killed by the true ½ heights  which 
Shugart OEMed from Matsushita.

Tom

-Original Message-
From: Eric Smith [mailto:space...@gmail.com] 
Sent: Wednesday, August 22, 2018 1:32 PM
To: Al Kossow; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Prototype IBM DemiDiskette drive

On Wed, Aug 22, 2018 at 1:09 PM, Al Kossow via cctalk  wrote:

> I just picked up a Model 350 on eBay, just because I'd never seen a 
> Shugart sub 5" drive.
>

Unfortunately I don't recall the model number, but there was a Shugart 5 1/4" 
drive that made it at least to prototype and field test around late
1980 or early 1981. It was supposed to be really inexpensive, but almost 
plug-compatible with standard drives like the SA400. Unlike the SA390, it did 
have electronics.

Instead of being built on an aluminum casting, it only had bent metal. The head 
stepping mechanism worked like an 8-track tape. It used a solenoid to advance 
one track inward; the only way to go outward was the next step from the 
innermost track returned to the outermost (track 0). The single track step time 
was incredibly slow; I think it was around 750ms, vs 40ms for an SA400.

My employer at the time, Apparat, then famous for NewDOS-80 for the TRS-80, had 
one for evaluation, but decided not to resell them. It would have required 
special software support, which Apparat could have put in NewDOS-80. Presumably 
patches could have been offered for other TRS-80 operating systems.

I wasn't told what the retail price of the drive would have been, but I don't 
think it would have sold well even at 1/4 the price of an SA400.

RE: DTC TakeTen media?

[Tom Gardner via cctalk]

According to DTC's 1987 prospectus the Company began limited shipments of its 
TakeTen 10-megabyte removable-cartridge disk drive in December 1986. The 
TakeTen is based on technology developed by Data Technology in collaboration 
with Eastman Kodak. The storage cartridge is manufactured by Verbatim 
Corporation (“Verbatim”), an Eastman Kodak subsidiary, and incorporates a 
high-performance flexible magnetic disk encased in a rigid plastic shell.

The Kodak drive was based on a license from DriveTec

DTC was acquired Qume and changed its name to Qume.

It stopped producing these sorts of drives in 1991

Tom


-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Wednesday, August 22, 2018 11:48 AM
To: CCtalk
Subject: DTC TakeTen media?

On the subject of oddball PC media, does anyone out there have media for
the DTC "Take Ten" cartridge drive?   I've got the drive here, still in
original shrink-wrap and packaging, but no media, so I don't have the faintest 
idea if it still works.

As the 5.25" cartridges only held 10MB, I suspect this was a flash-in-the-pan 
venture.  I'd never heard of one back in the day when everyone was using 
Bernoulli drives.

--Chuck

RE: First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

[Tom Gardner via cctalk]

As Chuck notes the shutter closing was different, the RPM was different and the 
interface was quite different.  Also different was the media coercivity, media 
thickness, data rate and physical drive form factor.  Enough differences such 
that the Sony 0A-D30 drive and medium could not interchange with what became 
the industry standard for 3½ FDDs and FDs.

What became the standard in all these areas and others was defined by the 
"Microfloppy Industry Committee" which was formed and led by folks from Shugart 
Corp.  At its peak it had at least 23 members.  In January 1983 Sony agreed to 
supply media comporting to the MIC standard.  Both Tandon and Shugart showed 
drives at Comdex 1982; who shipped first in 1983 is unknown.

Tom 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Thursday, August 23, 2018 12:20 PM
To: Tom Gardner via cctalk
Subject: Re: First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

On 08/23/2018 11:43 AM, Tom Gardner via cctalk wrote:
> Well it all depends upon what u mean by "first"
> 
> The Sony drive and cartridge were not compatible in many ways with 
> what became the physical, magnetic and electrical interface standards 
> for the 3.5-inch drive and cartridge.  The standards came out of the 
> "Microfloppy Industry Committee" (Google it with quotes) organized by Shugart 
> Corp.
> Either Shugart or Tandon was the first to ship drives compatible to 
> the standard.  Tandon probably did the first such cartridge.

I must confess some bewilderment.   Around 1981, I did some contract
work for an outfit called Preis for their portable computer.  I don't recall 
the nature of the work anymore, but I still have a copy of their BIOS for CP/M.

At any rate, the thing used the Sony 0A-D30 single-sided 600 RPM floppies, 
which held about half as much as the corresponding 8" media (in FM, about 
160KB). The major differences were that the Sony drive could access only 70 
cylinders, while the 8" drives could do 77.  In addition, the Sony spun at 600 
RPM, which allowed for the use of an 8"
drive interface, albeit at a reduced track capacity over the 8" drive.

One other notable aspect was that the Sony's 26-pin interface had no motor 
control line--the disk spun continuously, just like its 8"
relatives.  Similarly, it had a head-load solenoid, just like the 8"
drives.

Media-wise, I believe there was little difference between the Sony floppies and 
more modern DS2D commodity media.  I believe the disk shutters were not sprung, 
but were manual.

I used to have a couple of these drives, but scrapped them because the modern 
slow 3.5" drives did a better job of handling floppies.

Where Shugart fits into all of this, I have no idea.

--Chuck

An historical nit about FDDs

[Tom Gardner via cctalk]

Anyone know where the Step/Direction version of the FDD interface
originated.

So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and Memorex
650/651) used Step In/Step Out. The IBM 33FD Igar used direct control of the
motor.

The earliest Step/Direction FDD I can find is the Shugart 800 which first
shipped in September 1973.

Tom

RE: An historical nit about FDDs

[Tom Gardner via cctalk]

Hi Chuck

I agree it is easy to convert but I am surprised that a start-up would have the 
guts to change the "standard," whether it was Memorex, Potter or Century.  I 
think before the 33FD Memorex was the market leader but I could be wrong.  I've 
asked some SA founders the question.  Does anyone know any Potter or Century 
FDD people from the early 70s?

The early HDD interfaces I am aware of used a control cable with an 8-bit bus 
and a set of tag lines to define the bus - much more expensive to implement 
than the Step In/Step Out.

Regards,

Tom

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Wednesday, July 11, 2018 11:38 AM
To: Tom Gardner via cctalk
Subject: Re: An historical nit about FDDs

On 07/11/2018 11:12 AM, Tom Gardner via cctalk wrote:
> Anyone know where the Step/Direction version of the FDD interface 
> originated.
> 
> So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and 
> Memorex
> 650/651) used Step In/Step Out. The IBM 33FD Igar used direct control 
> of the motor.
> 
> The earliest Step/Direction FDD I can find is the Shugart 800 which 
> first shipped in September 1973.

Shugart is probably it, unless there's a hard drive interface that precedes it. 
 Mostly a minimal bit of logical difference between the Step in/Step out  and 
Step/Direction.  One can be converted to the other rather easily.

--Chuck

RE: An historical nit about FDDs

[Tom Gardner via cctalk]

Jon:  
The 23FD used on most S/370 mainframes had a two solenoid and swash plate 
actuator, pulse the in  solenoid to go in and the out solenoid to go out.
IBM SJ in those days was very cost conscious and preferred mechanical parts 
over electronic, hence this mechanism instead of the stepper motor implement by 
most (all?) other FDD manufacturers.

Chuck and Paul:
It's all relative - key to disk systems were taking off and the IBM 3470 
blessed the market.  The 1973 Shugart Associates business plan acknowledged 
Memorex as the then market leader in FDDs - MRX had Mohawk Data Systems and had 
shipped product to 45 potential customers.  SA estimated the market to be 327k 
units in 1973 growing to 633k by 1977, a big number in the 1970s and big enough 
to attract venture capital.  The big customer turned out to be Wang which SA 
won.

The FDD and FD were invented by a number of folks at IBM most of whom did join 
Al at Memorex see: 
https://en.wikipedia.org/wiki/History_of_the_floppy_disk#/media/File:FDD_patents_collage.png

All:
The first product was the SA900 not the SA800; it had a step/direction 
interface, and my guess now it was to save an IC or two in the circuits to 
drive the stepper motor.

Tom


 -Original Message-
From: Jon Elson [mailto:el...@pico-systems.com] 
Sent: Thursday, July 12, 2018 6:41 PM
To: Paul Berger; gene...@ezwind.net; discuss...@ezwind.net:On-Topic and 
Off-Topic Posts
Subject: Re: An historical nit about FDDs

On 07/12/2018 01:40 PM, Paul Berger via cctalk wrote:
> IBM created the 8" diskette as an inexpensive and reliable means of 
> loading microcode and shipped the first read only drives in 1971.
I am quite certain the original FDD on the 370/168 used a pair of solenoid 
coils to ratchet the head in and out.  I think the mechanism was a leadscrew 
and toothed wheel.  I heard a 370/168 loading a microcode overlay and it 
sounded like a machine gun, even in a pretty loud machine room.

I think the same scheme was used in the 370/145.

Jon


-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Thursday, July 12, 2018 12:05 PM
To: Paul Berger via cctalk
Subject: Re: An historical nit about FDDs

On 07/12/2018 11:40 AM, Paul Berger via cctalk wrote:

> Because IBM never sold the drives themselves and the market impact of 
> the first Memorex drive may not have been really big, there was no 
> real standard so when Shugart Associates released the SA800 its proved 
> to be very popular and its interface became the defacto standard.

One thing that escapes modern sensibilities is how expensive the first floppy 
disk systems were.  If you purchased one of the early microcomputers (IMSAI, 
Altair), a single-drive floppy disk system would
run more than the CPU unit.   Remember, there were initially no LSI
floppy controllers--on the MDS, Intel rolled their own as a 2-board Multibus 
set.  Some early systems used USART chips. IMSAI used another
8080 MPU for their controller.

Data separation was a fairly new problem too, as floppy ISV and general signal 
stability was not as good as most hard drives.  You're essentially using 
flexible, disposable media.

So initially, the market was not terribly large.

--Chuck

RE: Researching IBM rare equipment from 50s to 80s

[Tom Gardner via cctalk]

For the very early stuff u can't do much better than the US Army's Ballistic
Research Lab surveys, a number of which are on line at
http://www.ed-thelen.org/comp-hist/merged.html 

Tom

-Original Message-
From: Peter Van Peborgh [mailto:pe...@vanpeborgh.eu] 
Sent: Friday, December 14, 2018 2:42 AM
To: 
Subject: Researching IBM rare equipment from 50s to 80s

Fellow geeks of more mature vintage,

Do any of you guys know whether it is possible to find out to whom any IBM
equipment was sold back in the day? (Still chasing IBM 2321 Data Cell - I
never learn!)

Many thanks,

peter

|| |  |   || |  |   ||
Peter Van Peborgh
62 St Mary's Rise
Writhlington  Radstock
SomersetBA3 3PD
UK
01761 439 234
|| |  |   || |  |   ||

RE: Documentation for Xebec Owl (a 1984 SASI-disk-drive)

[Tom Gardner via cctalk]

In early 1984 I was in discussion with Jim Toreson of Xebec about selling
them Shugart Corp's SA700 drive mechanics for use in the Owl.  He went his
own way and I'm pretty sure the Owl embedded the controller into the drive
eliminating the ST-506 style interface.  That would account for the
additional firmware.

Toreson moved Xebec to Nevada and he is still there, see:
https://www.linkedin.com/in/jim-toreson-a514128/ 

Maybe he can identify an old engineer with some info in his/her attic or
garage ;-)

Tom

-Original Message-
From: Martin Peters [mailto:mar...@shackspace.de] 
Sent: Thursday, January 10, 2019 9:57 AM
To: cctalk@classiccmp.org
Subject: Documentation for Xebec Owl (a 1984 SASI-disk-drive)

Anyone here, owning a Xebec Owl and/or its documentation?

The Owl is a SASI-disk-drive from 1984. One could say that it's mostly a
Xebec S1410A mounted on a drive, thus eliminating the ST-506-interface.
The one I had my hands on seems to be a late version, called the Owl II
(20MB instead of 10MB). It shiped with a PC-SASI-controller for the
8-bit-ISA-bus (TTL) and 4KB Boot-ROM (in a 2764-EPROM).

The firmware of the Owl II itself seems to be more advanced and bigger than
that of the well-known Xebec-bridge-boards: The Owl has 16KB
(27128) of firmware, compared to the 4/8KB (2732/64) of a S1410/10A/20.
A lot of its commands are explained in the documentation of the S1420
controller, but it seems there are some commands missing, e.g. the command
0x0C.

The drive is not compatible with later SCSI equippment. The owner reported,
he did not manage to run it with a "modern" PC-SCSI-Controller and I'm not
surprised about this: Some commands and codes are incompatible to SCSI/CCS,
so the SENSE codes. There is also a command collision with the INQUIRY
command, u :(

Does someone own the/some/any documentation for the Owl?

It doesn't seem there's much more out there than this brochure:

http://www.bitsavers.org/pdf/xebec/brochures/Xebec_Owl_Datasheet_198410xx.pd
f

--map

RE: Pleas ID this IBM system....

[Tom Gardner via cctalk]

FWIW the tape drive is an IBM 2315 announced April 16, 1965 
  for 
use on low end S/360s.  Here is a brochure 
  as well as manuals at 
http://www.bitsavers.org/pdf/ibm/2415/ 

 

Tom

 

-Original Message-
From: P Gebhardt [mailto:p.gebha...@ymail.com] 
Sent: Sunday, April 07, 2019 4:08 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Pleas ID this IBM system

 

wow! ...Hopefully some larger museums or seriously envolved hobbyists within 
Germany can take care of this piece of history to save this nice piece of 
computer history. 

 

--- 

Pierre's collection of classic computers moved to:  
 http://www.digitalheritage.de

 

 

 

 

 

 

Am Samstag, 6. April 2019, 16:04:26 MESZ hat jos via cctalk < 
 cctalk@classiccmp.org> Folgendes geschrieben: 

 

 

 

 

 

 

The seller clearly has no idea, but the starting price is right !

 

 

 
https://www.ebay.de/itm/seltene-Anlage-Puma-Computer-IBM-2020/202646831828?hash=item2f2eb142d4:g:izoAAOSwhV1cpw

 

 

 

Jos

 

 

RE: Damaged LTO tapes

[Tom Gardner via cctalk]

Based upon my interviews for the Computer History Museum of IBM personnel
involved in the development of LTO and its medium, I'd expect it to be very
difficult to damage an LTO tape
See: https://www.computerhistory.org/collections/catalog/102738025
particularly sessions 1 and 5

Tom

-Original Message-
From: Zane Healy [mailto:heal...@avanthar.com] 
Sent: Friday, May 24, 2019 2:29 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Damaged LTO tapes

Anyone have any experience on how hard it is to damage an LTO tape.  I mean
damage them to the point they split at the seam.

Zane

RE: What is this?

[Tom Gardner via cctalk]

There is a section in Bashe et al, Early IBM Computers that suggests Walnut 
only went to the CIA.

 

The follow on project was  Cypress beginning in 1962:

“The main Cypress system, designed to store all information in digital form, 
was sometimes called the Trillion-bit File. This system was very exploratory 
and expensive; it necessitated mastery over several technologically advanced 
engineering fields, among them electron- beam recording. (The project continued 
for several more years and five systems were delivered—three to AEC 
laboratories and two to NSA.)101

It became the 1360 Photo Digital Store

“101. Kean, 1977: pp. 79-80. Under the name IBM 1360 Photo-Digital Storage 
System, the first system was delivered on 30 September 1967 to the Lawrence 
Radiation Laboratory, Livermore, California; see R. M. Furman, 15 May 1968: 
“IBM 1360 Photo-Digital Storage System,” IBM Technical Report. For a technical 
description of the 1360, see J. D. Kuehler and H. R. Kerby, 1966: “A 
Photo-Digital Mass Storage System,” Proceedings of the Fall Joint Computer 
Conference, pp. 735-742. A simpler system, which stored images on microfilm, 
was announced as the IBM 1350 Photo Image Retrieval System in May 1966 and soon 
withdrawn for lack of sufficient acceptance.”

Tom

 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Friday, May 10, 2019 1:13 PM
To: Donald via cctalk
Subject: Re: What is this?

 

On 5/10/19 12:45 PM, Donald via cctalk wrote:

>   
> http://www.myimagecollection.com/webpics/unknownmachine.jpg

> 

>  

> 

> The model number looks like 9603.  Can't tell for sure.  The box in 

> back has the 14xx flavor.

 

IBM 9603 WALNUT - Microfilm image storage and retrieval system.   Read

about it on PDF page 13 here:

 

 

 
http://nopr.niscair.res.in/bitstream/123456789/28351/1/ALIS%2014%282%29%2062-75.pdf

 

Circa 1960.

 

There's more on the web; just search on "IBM WALNUT"

 

--Chuck

 

RE: Unknown 1970 Tapedrive

[Tom Gardner via cctalk]

The Sangamo Electric Co  . 
manufactured  electrical meters, time switches and sonar and radio equipment, 
among other items, in Springfield, IL from the 1890s until 1978.

If your US house is old enough u might still have one of their meters on the 
wall

 

The device is either an instrumentation or an audio recorder, see: 
https://americanhistory.si.edu/collections/search/object/SILNMAHTL_16729 

 

tom

 

-Original Message-
From: jos [mailto:jos.dree...@greenmail.ch] 
Sent: Tuesday, April 30, 2019 9:28 AM
To: Chuck Guzis via cctalk
Subject: Re: Unknown 1970 Tapedrive

 

 

 

On 29.04.19 22:28, Chuck Guzis via cctalk wrote:

> On 4/29/19 12:56 PM, Jos Dreesen via cctalk wrote:

> 

>> 

>> 1970, also all TTL is dated 1969 or 1970.

>> 

>> Jos

> 

> That would fit right in with a key-tape scheme.   Can you tell if the

> capstan motor is a stepper?

> 

> --Chuck

> 

> 

 

I put up some more pics (Tapehead & capstan drive). It does not use stepper.

 

It seems it was made by US firm Sangamo, as is etched in some of the PCB's

 

In view of the head's condition I will not persue this further.

 

 

Jos

 

 

RE: Telex 20 Meg 10 platter very heavy monster drive needed drop line off list..r

[Tom Gardner via cctalk]

ISS was an independent company in the era (late 60s) of the 714 (IBM 2314 
compatible).  It was later acquired by Itel (a leasing company) and then by 
Univac and sort of disappeared in the 80s.

Depending upon your application almost any plug compatible 2314 might work or 
could be made to work.  The interfaces were very much 2314 like except the PCMs 
and OEMs didn't use IBMs +/- 1.5v signaling levels on the interface but instead 
used DTL driver/receiver signaling.  There was also some weirdness in the power 
sequencing all of which can be worked around if u are up to it.

Tom

-Original Message-
From: ED SHARPE [mailto:couryho...@aol.com] 
Sent: Monday, April 22, 2019 11:37 AM
To: cctalk@classiccmp.org; a...@bitsavers.org
Subject: Re: Telex 20 Meg 10 platter very heavy monster drive needed drop line 
off list..r

Thanks  Al   yes, that  is  the  one.

and  as  I  recall   ISS  was a   offshoot  on   univac Do   you  have  any?
Thanks Ed#

In a message dated 4/22/2019 11:34:58 AM US Mountain Standard Time, 
cctalk@classiccmp.org writes:
Thanks  Al   yes, that  is  the  one.

and  as  I  recall   ISS  was a   offshoot  on   univac?In a message dated 
4/22/2019 11:21:50 AM US Mountain Standard Time, cctalk@classiccmp.org writes:

On 4/22/19 11:05 AM, ED SHARPE wrote:> Al,  the  drive   you mention at  its  
largest   was  7.5 meg  and  6  platters... notthe   one Telex bought their 
drives from ISS.You're looking for a ISS 714 (ca. 1970) 2314 
compat.https://ia800608.us.archive.org/15/items/TNM_Information_Storage_Systems_-_714_Disk_Storag_20170630_0180/TNM_Information_Storage_Systems_-_714_Disk_Storag_20170630_0180.pdf
a...@bitsavers.org;cctalk

Tape History - Freeman Reports

[Tom Gardner via cctalk]

Hi

 

I'm sure some of us all remember Freeman Reports as the chronical of the
tape industry well into this century.  Ray Freeman and his partner and
successor Bob Abraham published these reports from at least 1983 until 2007
but with Bob's death in 2007 the reports and backup files apparently wound
up in a dumpster.  But Ray, Bob and Jim Porter did exchange copies of their
reports so thanks to Jim the Computer History Museum has almost all of the
Freeman Reports in their permanent collection.

 

There appear to be a few copies missing from the collection.  A complete
list of what the museum has and what maybe missing is posted at
http://mrxhist.org/tom94022/FreemanRpt.pdf.  In summary what may be missing
are:

Computer tape outlook - . half-inch products: 1994, 1985, 1990 & 1992

Computer tape outlook - . cassette/cartridge: 1984 & 1985

 

Computer tape outlook  -  all tape: 1997-2000  (as the market consolidated
towards LTO so did the reports J

 

Optical data storage outlook: 1985, 1988 & 1998

 

Mass storage/Library storage outlook: 1992, 1993, 1997 & 2000 

 

So before they all get trashed please look and see if you happen to have any
of the possibly missing editions in your garage, attic or any other
repository.

 

Contact me off line if you can help.

 

Tom

 

One of Bay Area's last Fry's Electronics stores closes

[Tom Gardner via cctalk]

Palo Alto Fry’s closing 

 .  Sad, but not the end of an era – apparently the loss of lease

 

I remember visiting an early Fry’s (first?) in Sunnyvale (541 Lakeside Dr?, 
near Oakmead and around the corner from Shugart Associates where I then 
worked).  I marveled at the selection of steaks, diet cokes, resistors, 
capacitors, ICs, etc.  They had partially converted a supermarket into an 
electronics store but I heard they at first kept the food to keep some cash 
flow.  I think I bought steaks J  The engineers and technicians at Shugart more 
than once ran over there to get breadboard parts.

 

 

Standard Cocktail Napkin Size [WAS: RE: history is hard (was: Microsoft open sources GWBASIC)}

[Tom Gardner via cctalk]

On Sunday, May 24, 2020 11:23 AM Fred Cisin via cctalk wrote in part:

>> On Sun, 24 May 2020, Tom Gardner via cctalk wrote:
>>The final media size was determined by Shugart Engineering led by Al 
>> Chou from the size of the 8-track tape drive that the 5¼-inch FDD was 
>> to replace in Wang and other systems.  As near as I can tell it was 
>> not the same size as a “standard” cocktail napkin.

>"standard"??!?
>"I believe in standards.  Everyone should have [a unique] one [of their
own]." - George Morrow I have seen napkins that are about 5.25".

I did attempt to see if there is a "standard" cocktail napkin size and as
best I can tell it is today 5-inches square not 5¼-inches square.

A friend who is a veteran of the paper products industry provided me an
actual cocktail napkin circa 1980 (a promotional give away for his business)
that he recalls was procured to the then standard size which I measured as
5-inches square.  Apparently cocktail napkins have not deflated over the
intervening 40 years :-)

This supports Adkisson's recollection that the customer wanted something
about the size of a cocktail napkin and Chou's description of the
development process that tried to maximize the size of the disk that could
be received in a drive which in turn was designed to fit into the then
existing 8-track tape drive slot.

Tom

RE: history is hard (was: Microsoft open sources GWBASIC)

[Tom Gardner via cctalk]

Fred Cisin [mailto:ci...@xenosoft.com]  wrote on Saturday, May 23, 2020
11:28 PM





Some don't matter; some can be enough to ruin a good anecdote; some create 

a different story.

 

I'm saddened that Jim Adkisson and Don Massaro of Shugart have changed 

their story and now deny that the size of the 5.25" disk was based on Dr. 

Wang pointing to a bar napkin.  The "Bar Napkin Disk" was a GREAT 

anecdote; now ruined.

 

http://archive.computerhistory.org/resources/access/text/2013/05/102657925-0
5-01-acc.pdf

 



 

It's probably OK for Fred to be saddened at the demise of a good story but
isn't it better to have the true story?

 

Neither Jim Adkisson nor Don Massaro of Shugart ever promulgated the urban
legend of Dr. Wang and the napkin in the bar - as near as I can tell it was
invented from whole cloth by Jim Porter who repeated it so many times that
it became legend.

 

The final media size was determined by Shugart Engineering led by Al Chou
from the size of the 8-track tape drive that the 5¼-inch FDD was to replace
in Wang and other systems.  As near as I can tell it was not the same size
as a “standard” cocktail napkin.

 

The idea for a smaller FDD with cocktail napkin sized medium did come
through Adkisson but it originated at his customers such as Lanier,
Phillips and Varisyst among others before it was taken to Wang.

 

History is hard - I researched this for the Computer History Museum and
prevented the legend from making it into their exhibits.

 

Tom

 

 

Early 3M Computer Tape Type Numbers

[Tom Gardner via cctalk]

I'm trying to figure out what were the earliest Type numbers for 3M ½-inch 
reel-to-reel computer tape

As best I can find, 3M began marketing a Type 777 computer tape about 1967.  
The Type 700 appears to be somewhat later.  But 3M sold computer tape directly 
to at least government customers (e.g. NSA, Social Security) in the 1950s.  The 
also notably OEMed tape to IBM who rebranded it under an IBM label until the 
late 1960s at which point with the help of Sony IBM began manufacturing its own 
computer tape.

Anyone have any idea of the Type number for 3M computer tapes earlier than Type 
777?

There might be a place for some of these older Types at the CHM if anyone knows 
of any still in existence.

Tom

PS:  There is a lot of information on 3M audio tape Type numbers as at 
http://www.aes.org/aeshc/docs/3mtape/aorprod-cust.pdf but computer tape seems 
to be an orphan

RE: Early 3M Computer Tape Type Numbers

[Tom Gardner via cctalk]

Also FWIW 3M Types 108, 109, 128 and 159 were advertised in 1958 as 
“instrumentation tapes” used for “critical recording work” on “… computers …”

 

From: Tom Gardner [mailto:t.gard...@computer.org] 
Sent: Sunday, June 28, 2020 5:08 PM
To: 'Paul Koning'; 'cctalk@classiccmp.org'
Subject: RE: Early 3M Computer Tape Type Numbers

 

FWIW this is an announcement of a 3M brochure from a 1957 Datamation:

 

Magnetic Tape for Instrumentation,  an 8-page brochure, covers six types of 
"Scotch" brand instrumentation tapes for use in telemetering and airborne 
recording, machine tool control systems, computers, geophysical recording, and 
other instrumentation applications. Included are charts listing physical and 
magnetic properties of each of the precision tapes and a comparison chart 
summary of major factors in selecting a tape for a particular application. 

Minnesota Mining & Mfg. Co., 900 Bush St., St. Paul 6, Minn.

Circle 113 on Reader Service Card

 

Apparently  3M “Instrumentation tapes” can be used for “computers”

 

AFAIK 3M early “Instrumentation tape” types include Type 148/149 and Type 
480/481 but both were announced after the 1957 brochure mentioned above

 

It looks like all 3M “Type” tapes of this early era were available in a variety 
of widths, from ¼-inch to 2 inches

 

-Original Message-
From: Paul Koning [mailto:paulkon...@comcast.net] 
Sent: Friday, June 26, 2020 11:44 AM
To: Tom Gardner
Cc: cctalk@classiccmp.org  
Subject: Re: Early 3M Computer Tape Type Numbers

 

 

 

> On Jun 26, 2020, at 1:46 PM, Tom Gardner <  
> t.gard...@computer.org> wrote:

> 

> Paul

> 

> Thanks, I had found this ad a while ago but thought it was �-inch.  Upon 
> careful reading all the notes I found, "Errors per roll based on recording 7 
> tracks on rolls �" x 2500'. "

> 

> It looks like 3M may have called their computer tapes "Instrumentation" tape 
> until the late 60s

> 

> Tom

 

"Instrumentation tape" sounds like a reference to instrumentation recorders, 
which were devices used to record N channels of analog data.  Typically this 
was done by FM-modulating that data for the actual recording process.  I've 
seen references to heads for such machines in widths from 1/4 inch to 2 inches 
depending on the number of channels needed.  I believe instrumentation tape was 
usually supplied on reels that look like professional audio tape reels -- metal 
flanged reels with hubs somewhat larger than a standard computer tape hub, with 
3 small notches.

 

Some early computers used tape like that for data recording; for example, the 
Electrologica X1 used 1/2 inch instrumentation tape reels, recording data at 
400 DPI (NRZI I think) in 10 (!) tracks.  Those were vaguely like DECtape -- 
random access rewritable blocks -- but with variable rather than fixed length 
blocks. 

 

Recovering data from such reels is an interesting problem today.

 

paul

 

RE: Early 3M Computer Tape Type Numbers

[Tom Gardner via cctalk]

FWIW this is an announcement of a 3M brochure from a 1957 Datamation:

 

Magnetic Tape for Instrumentation,  an 8-page brochure, covers six types of 
"Scotch" brand instrumentation tapes for use in telemetering and airborne 
recording, machine tool control systems, computers, geophysical recording, and 
other instrumentation applications. Included are charts listing physical and 
magnetic properties of each of the precision tapes and a comparison chart 
summary of major factors in selecting a tape for a particular application. 

Minnesota Mining & Mfg. Co., 900 Bush St., St. Paul 6, Minn.

Circle 113 on Reader Service Card

 

Apparently  3M “Instrumentation tapes” can be used for “computers”

 

AFAIK 3M early “Instrumentation tape” types include Type 148/149 and Type 
480/481 but both were announced after the 1957 brochure mentioned above

 

It looks like all 3M “Type” tapes of this early era were available in a variety 
of widths, from ¼-inch to 2 inches

 

-Original Message-
From: Paul Koning [mailto:paulkon...@comcast.net] 
Sent: Friday, June 26, 2020 11:44 AM
To: Tom Gardner
Cc: cctalk@classiccmp.org
Subject: Re: Early 3M Computer Tape Type Numbers

 

 

 

> On Jun 26, 2020, at 1:46 PM, Tom Gardner <  
> t.gard...@computer.org> wrote:

> 

> Paul

> 

> Thanks, I had found this ad a while ago but thought it was �-inch.  Upon 
> careful reading all the notes I found, "Errors per roll based on recording 7 
> tracks on rolls �" x 2500'. "

> 

> It looks like 3M may have called their computer tapes "Instrumentation" tape 
> until the late 60s

> 

> Tom

 

"Instrumentation tape" sounds like a reference to instrumentation recorders, 
which were devices used to record N channels of analog data.  Typically this 
was done by FM-modulating that data for the actual recording process.  I've 
seen references to heads for such machines in widths from 1/4 inch to 2 inches 
depending on the number of channels needed.  I believe instrumentation tape was 
usually supplied on reels that look like professional audio tape reels -- metal 
flanged reels with hubs somewhat larger than a standard computer tape hub, with 
3 small notches.

 

Some early computers used tape like that for data recording; for example, the 
Electrologica X1 used 1/2 inch instrumentation tape reels, recording data at 
400 DPI (NRZI I think) in 10 (!) tracks.  Those were vaguely like DECtape -- 
random access rewritable blocks -- but with variable rather than fixed length 
blocks. 

 

Recovering data from such reels is an interesting problem today.

 

paul

 

RE: Early 3M Computer Tape Type Numbers

[Tom Gardner via cctalk]

Paul

Thanks, I had found this ad a while ago but thought it was ¼-inch.  Upon 
careful reading all the notes I found, "Errors per roll based on recording 7 
tracks on rolls ½" x 2500'. "

It looks like 3M may have called their computer tapes "Instrumentation" tape 
until the late 60s

Tom


-Original Message-
From: Paul Koning [mailto:paulkon...@comcast.net] 
Sent: Thursday, June 25, 2020 5:15 PM
To: Chuck Guzis; cctalk@classiccmp.org
Subject: Re: Early 3M Computer Tape Type Numbers



> On Jun 25, 2020, at 5:14 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 6/25/20 1:55 PM, Tom Gardner via cctalk wrote:
>> I'm trying to figure out what were the earliest Type numbers for 3M 
>>  -inch reel-to-reel computer tape
>> 
>> As best I can find, 3M began marketing a Type 777 computer tape about 1967.  
>> The Type 700 appears to be somewhat later.  But 3M sold computer tape 
>> directly to at least government customers (e.g. NSA, Social Security) in the 
>> 1950s.  The also notably OEMed tape to IBM who rebranded it under an IBM 
>> label until the late 1960s at which point with the help of Sony IBM began 
>> manufacturing its own computer tape.
>> 
>> Anyone have any idea of the Type number for 3M computer tapes earlier than 
>> Type 777?
>> 
>> There might be a place for some of these older Types at the CHM if anyone 
>> knows of any still in existence.
>> 
>> Tom
>> 
>> PS:  There is a lot of information on 3M audio tape Type numbers as 
>> at http://www.aes.org/aeshc/docs/3mtape/aorprod-cust.pdf but computer 
>> tape seems to be an orphan
> I probably do--but I'm going to have to look through my logs.  Old 3M 
> tape is terrible for binder that sticks to everything.  Before 
> processing the stuff, I have to lubricate it.

Except for DECtape, of course.  That's 3M 340 or 341, the spec (from Nov 1966) 
is here: http://www.bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf

paul

RE: BYTE Magazines

[Tom Gardner via cctalk]

My understanding is that the Computer History Museum has a complete bound set - 
maybe Al can confirm

And there is likely a fairly complete set at Stanford's GSB periodicals 
collection.

Other computer or technical history museums might want a fairly complete set; 
e.g., Charles Babbage Institute, and u would have to check them one by one.

Tom

-Original Message-
From: Kevin Parker [mailto:tras...@internode.on.net] 
Sent: Tuesday, June 02, 2020 4:15 PM
To: cctalk@classiccmp.org
Subject: BYTE Magazines

I know the response to this might be quite subjective and depends on your 
particular interests.

Do BYTE magazines have any collectability (maybe even from a historical 
perspective or something else)?

I have to make some decisions about space (the perennial problem for a 
collector of course) and I have quite a few of these taking up a few shelves.

Thank you.


Kevin Parker

First SCSI HDD - Priam 806 8-inch?

[Tom Gardner via cctalk]

It turns out the Priam 806 8-inch SCSI HDD circa 1984 is likely the first
HDD to have a native SCSI interface.  It shipped a few months before the
Xebec Owl which is likely second.  AFAIK all earlier units had a bridge
controller to a more conventional interface.  

If anyone has any different info as to dates and models I would appreciate
it.

Does anyone know where a Priam 806 might be, or have any documentation?  The
former probably belongs in a museum and the latter on Bitsavers.  I will
help facilitate either.

Tom
t.gard...@computer.org

Webinar: Ethernet's Emergence from Xerox PARC: 1975-1980

[Tom Gardner via cctalk]

Ethernet invented in 1973-74 at Xerox PARC in Palo Alto, CA, evolved over
many years. 

 

This April 13th Webinar will trace the history and development of Ethernet
as a 10 Mb/s product up through the release of the DIX (DEC-Intel-Xerox)
spec in 1980. This was the starting point for the ongoing IEEE 802.3
Standard activities. Speakers include Gorden Bell, Dave Liddle, Bob Metcalfe
and seven other pioneers who were there for the transition.

 

More detail at   SVTHC website

 

Register
 

 

Tom

 

Origin of "partition" in storage devices

[Tom Gardner via cctalk]

There is a discussion of the origin of the term "partition" in storage
devices such as HDDs at:
https://en.wikipedia.org/wiki/Talk:Disk_partitioning#Where_did_the_term_%22p
artition%22_originate?

It seems clear it was used in memory well before HDDs but when it got
started there is unclear.
* IBM PC DOS v2 was an early user in 1983 with FDISK and its first PC
support of HDDs
* UNIX, Apple OS's and IBM mainframe all seem to come later.

Partitioning as a "slice" probably predates IBM PC DOS v2

Would appreciate some recollections about DEC usage, other minicomputers and
the BUNCH.

You can either post directly to Wikipedia or let me know; links to
references would greatly be appreciated

Tom

RE: Origin of "partition" in storage devices

[Tom Gardner via cctalk]

FWIW a Google search:  "partition 
site:http://www.bitsavers.org/pdf/dec/pdp11/rt11; returns no relevant hits 
prior to 1983

I suspect that ESDI and MFM controllers emulating RL/RK disks are also later 
than 1983

Tom

-Original Message-
From: Zane Healy [mailto:heal...@avanthar.com] 
Sent: Monday, January 31, 2022 12:40 PM
To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts
Cc: t.gard...@computer.org; Tom Gardner
Subject: Re: Origin of "partition" in storage devices

On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk  
wrote:
> 
> Both of these are memory partitions.   The only OS I can think of predating 
> the ones you mentioned is RT-11, the later versions (V2 did not have them).  
> When did Unix first get partitions?
> 
>   paul

Partitions are pretty important in RT-11 v5.x, after all, there is the 
partition size limit, so you have to have multiple partitions for almost any 
HD, except very small ones.

Let�s not forget hardware enforced partitioning, the WEQSD/04 ESDI controller 
comes to mind.  It see�s a single large ESDI HD as a single disk, but you can 
partition it on the controller, and the OS sees each partition as a separate 
physical disk.  I seem to remember some MFM controllers that made the MFM drive 
appear to be RL01/RL02 or RK05 packs.

Zane

Re: Origin of "partition" in storage devices

[Tom Gardner via cctalk]

A somewhat broader search found the 1984 RT-11 System Release Notes with the 
following:

 

1.4.2.4 Logical Disk Subsetting Handler (LD) - The logical disk subsetting 
handler lets you define logical disks, which are subsets of physical disks. You 
define logical disks by assigning a logical disk unit number to a file on a 
physical disk. You can then use the logical disk as though it were a physical 
disk.

AA-5286F-TC-T1_RT-11_System_Release_Notes_Jul84.pdf (bitsavers.org) 

  p15/102

 

Suggests DEC had not yet adopted the term “partition” for a segment of a disk

 

Tom

 

-Original Message-
From: Tom Gardner [mailto:tom94...@comcast.net] 



FWIW a Google search:  "partition 
site:http://www.bitsavers.org/pdf/dec/pdp11/rt11; returns no relevant hits 
prior to 1983

 

I suspect that ESDI and MFM controllers emulating RL/RK disks are also later 
than 1983

 

Tom

 

-Original Message-

From: Zane Healy [  mailto:heal...@avanthar.com] 

Sent: Monday, January 31, 2022 12:40 PM

To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts

Cc:   t.gard...@computer.org; Tom Gardner

Subject: Re: Origin of "partition" in storage devices

 

On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk < 
 cctalk@classiccmp.org> wrote:

> 

> Both of these are memory partitions.   The only OS I can think of predating 
> the ones you mentioned is RT-11, the later versions (V2 did not have them).  
> When did Unix first get partitions?

> 

> paul

 

Partitions are pretty important in RT-11 v5.x, after all, there is the 
partition size limit, so you have to have multiple partitions for almost any 
HD, except very small ones.

 

Let�s not forget hardware enforced partitioning, the WEQSD/04 ESDI controller 
comes to mind.  It see�s a single large ESDI HD as a single disk, but you can 
partition it on the controller, and the OS sees each partition as a separate 
physical disk.  I seem to remember some MFM controllers that made the MFM drive 
appear to be RL01/RL02 or RK05 packs.

 

Zane

 

 

RE: Question about DECtape formulation

[Tom Gardner via cctalk]

> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech
 wrote:
> 
>> ...
> 
> As to the real reason I was doing this: Most of my tapes are un-boxed and
have suffered being in a dusty area (before I got them) with the dust
forming a sort of 'crust' on the outside of the tape.  It's only on the
first wrap or so, but it's enough that it keeps those handy vinyl cohesive
tapes from sticking.  For that reason, I was trying to find something to
clean of this dusty gunk so the vinyl strip would hold the tape into a
spooled condition. It was the side-effect of this effort that lead me to the
discovery if this "removable layer" on the DECtape.
> 

I talked to a friend who was at DEC during the days of DECTape and
thereafter, his comment:
..."I think it is a thin version of the base material, some flavor of
polyester film.  Most likely a 3M tape.  The bit density is so low a little
spacing doesn't matter much.
...The UNISERVO I, of Univac I, tape drives had a separate spool of clear
very thin film that was clock motor wound across the head when tape was
moving, since the phosphor bronze plated tape was very abrasive.  That
existed long before LINCtape/DECtape."

Note that LINCtape is DECtape :-)

Tom

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

I suggest if we are talking about an emulator it really isn't necessary to have 
the entire disk in DRAM, two tracks of DRAM acting as a buffer with a modern 
HDD holding the emulated drive's data should be fast enough to keep any old 
iron controller operating without missing any revolutions.  The maximum 
unformatted track length of any old iron drive is well known and therefore one 
can allocate the number of blocks sufficient to store a full track and then 
write every track, gaps and all to the modern disk.  Given the data rate, track 
size and sequential seek times of a modern HDD one should be able to fill then 
next track buffer before the current track buffer is read into the controller.  
If two track buffers and an HDD isn't fast enough then one could add a track 
buffer or two or go to SSD's.

This was the approach IBM used in it's first RAMAC RAID where I think they had 
to buffer a whole cylinder but that was many generations ago

Tom

-Original Message-
From: Guy Sotomayor [mailto:g...@shiresoft.com] 
Sent: Wednesday, April 13, 2022 10:02 AM
To: cct...@classiccmp.org
Subject: Re: idea for a universal disk interface

I've had a similar project in the works for a while (mainly for ESDI and SMD).

I think the main issue you're going to face is that what you need to do for 
something like ESDI or SMD (or any of the bit serial interfaces) is going to be 
radically different than something like IDE or SCSI.  This is not just the 
interface signals but also what's needed in the FPGA as well as the embedded SW.

For example, for the ESDI and SMD interface in order to meet the head switch 
times (1-2 microseconds) requires that a full cylinder be cached in HW.  Once 
you do that and look at the timings to move a max cylinder between the HW cache 
(that will serialize/de-serialize the data over the
interface) and storage, you'll see that the only way to have any reasonable 
performance (e.g. not have seek times be > 40ms for *any*
seek) is to cache the entire drive image in DRAM and lazily write back dirty 
tracks.

I've been looking at the Xylinx Zynq SoCs for this (mainly the Zynq 7020 for 
single drive emulation and the Zynq Ultrascale+ for up to 4 drives).  In my 
case the HW, FPGA logic and SW will share significant portions but they will 
not be identical.  In my case there is no need for an external PC (just adds 
complexity) other than something to do basic configuration (e.g. drive 
parameters such as number of heads, number of cylinders, etc) which will 
actually be over USB/serial.  The actual persistent storage will be an SD card 
since all reading will be done at "boot time" and writes will be handled in a 
lazy manner (since the writes will first go to the DRAM based upon time or 
seek).

It may also be sufficient for configuration purposes to have a file
(text) on the SD card that defines the configuration so no external 
interactions would be necessary.  I'm still thinking about that one.  ;-)

TTFN - Guy

On 4/12/22 22:35, shad via cctech wrote:
> Hello,
> I'm a decent collector of big iron, aka mini computers, mainly DEC and DG.
> I'm often facing common problems with storage devices, magnetic discs and 
> tapes are a little prone to give headaches after years, and replacement 
> drives/media in case of a severe failure are unobtainable.
> In some cases, the ability to make a dump of the media, also without a 
> running computer is very important.
>
> Whence the idea: realize an universal device, with several input/output 
> interfaces, which could be used both as storage emulator, to run a computer 
> without real storage, and as controller emulator, to read/write a media 
> without a running computer.
> To reduce costs as much as possible, and to allow the better compatibility, 
> the main board shall host enough electrical interfaces to support a large 
> number of disc standard interfaces, ideally by exchanging only a personality 
> adapter for each specific interface, i.e. connectors and few components.
>
> There are several orders of problems:
> - electrical signals, number and type (most disk employ 5V TTL or 3.3V 
> TTL, some interfaces use differential mode for some faster signals?)
> - logical implementation: several electrical signals are used for a 
> specific interface. These must be handled with correct timings
> - software implementation: the universal device shall be able to 
> switch between interface modes and be controlled by a remote PC
>
> I suppose the only way to obtain this is to employ an FPGA for logic 
> implementation of the interface, and a microprocessor running Linux to handle 
> software management, data interchange to external (via Ethernet). This means 
> a Xilinx Zynq module for instance.
> I know there are several ready devices based on cheaper microcontrollers, but 
> I'm sure these can't support fast and tight timing required by hard disk 
> interfaces (SMD-E runs at 24MHz).
>
> The main board should include a large enough array of 

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

The IMI 7710 34 pin flat cable interface is a variant on the SMD dumb interface 
which could be controlled by a UDI (universal disk interface) if someone cared 
enough to build an adapter and then program the UDI to deal with IMI's specific 
track format and peculiar command/status protocol.  CalComp would be easier, 
but the question remains would either be worth the effort given their 
relatively low unit shipments compared to the other interfaces?

Tom

-Original Message-
From: r.stricklin [mailto:b...@typewritten.org] 
Sent: Wednesday, April 13, 2022 8:12 PM
To: t.gard...@computer.org; Tom Gardner; General Discussion: On-Topic Posts
Subject: Re: idea for a universal disk interface



> On Apr 13, 2022, at 11:51 AM, Tom Gardner via cctech  
> wrote:
> 
> There are a few others like ANSI and CalComp but they are probably not worth 
> investigating.
> 

They are if you�re someone who has a machine using one of these interfaces, or 
e.g. the 40-pin �IMI bus�, or whatever else.



ok
bear.=

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

I haven't looked it up but I bet the head switch time is a lot longer than 1-2 
usec - that's what the leading gap is for and the sync took most of the gap 
back in those days.

 

The issue is sustained data rate isn't it?  The ESMD raw data rate is 24 Mb/s 
but the formatted data is something like 80% of that or maybe 2.5 MB/sec.  A 
modern HDD in sequential mode can sustain a much higher rate, e.g. Seagate SAS 

  at 520 MB/sec.  My understanding is that the sectors are slipped and/or 
cylinders are horizontal so that head switching doesn't lose any revolutions.  
Maybe one would run into a problem at the cylinder seek moment so maybe one 
would have to keep each full emulated cylinder on the modern drive’s cylinder, 
but with Terabytes of data on a modern drive who cares about some wasted 
storage 

 

Tom

 

-Original Message-
From: Guy Sotomayor [mailto:g...@shiresoft.com] 
Sent: Friday, April 15, 2022 10:56 AM
To: t.gard...@computer.org; cct...@classiccmp.org
Subject: Re: idea for a universal disk interface

 

I ran the numbers for Zynq FPGAs.  First of all for ESDI and SMD the head 
switch time is 1-2us (basically the time it takes for the clocks to re-lock on 
the new data).

 

Two tracks isn't sufficient (which is the "other" track...you will be wrong).

 

So I decided to go and have a full cylinder (I'm allowing for up to 32KB tracks 
and up to 16 heads) which is 512KB.  The Zynq DMA from HW block RAM to DRAM (at 
500MB/s) is ~1ms.  Given that the previous cylinder could be dirty (e.g. has 
written data), the worst case seek time is ~2ms.  This allows me to emulate any 
seek latency curve(s) I want.

 

In my design, any dirty data is written back to storage in a lazy manner so the 
performance of the storage isn't really an issue.

 

I should note that the Zynq 7020 module has 1GB of DRAM on it, so there is no 
additional cost to just put the entire disk contents in DRAM and I'm using the 
attached SD Card interface for storage (so you can use a

$10 SD Card for storage).  Adding a high speed disk interface (e.g. 

MD.2, PCIe, or other serially attached storage) would add additional cost in 
terms of having to create the interface as well as a reasonably fast drive and 
I don't see the advantage.

 

I'm planning on using a Zynq UltraScale+ module to allow for larger disks and 
multiple disk emulations (it has more block RAM and 4GB of DRAM on the module).

 

TTFN - Guy

 

On 4/14/22 23:34, Tom Gardner wrote:

> I suggest if we are talking about an emulator it really isn't necessary to 
> have the entire disk in DRAM, two tracks of DRAM acting as a buffer with a 
> modern HDD holding the emulated drive's data should be fast enough to keep 
> any old iron controller operating without missing any revolutions.  The 
> maximum unformatted track length of any old iron drive is well known and 
> therefore one can allocate the number of blocks sufficient to store a full 
> track and then write every track, gaps and all to the modern disk.  Given the 
> data rate, track size and sequential seek times of a modern HDD one should be 
> able to fill then next track buffer before the current track buffer is read 
> into the controller.  If two track buffers and an HDD isn't fast enough then 
> one could add a track buffer or two or go to SSD's.

> 

> This was the approach IBM used in it's first RAMAC RAID where I think 

> they had to buffer a whole cylinder but that was many generations ago

> 

> Tom

> 

> -Original Message-

> From: Guy Sotomayor [  mailto:g...@shiresoft.com]

> Sent: Wednesday, April 13, 2022 10:02 AM

> To:   cct...@classiccmp.org

> Subject: Re: idea for a universal disk interface

> 

> I've had a similar project in the works for a while (mainly for ESDI and SMD).

> 

> I think the main issue you're going to face is that what you need to do for 
> something like ESDI or SMD (or any of the bit serial interfaces) is going to 
> be radically different than something like IDE or SCSI.  This is not just the 
> interface signals but also what's needed in the FPGA as well as the embedded 
> SW.

> 

> For example, for the ESDI and SMD interface in order to meet the head 

> switch times (1-2 microseconds) requires that a full cylinder be 

> cached in HW.  Once you do that and look at the timings to move a max 

> cylinder between the HW cache (that will serialize/de-serialize the 

> data over the

> interface) and storage, you'll see that the only way to have any 

> reasonable performance (e.g. not have seek times be > 40ms for *any*

> seek) is to cache the entire drive image in DRAM and lazily write back dirty 
> tracks.

> 

> I've been looking at the Xylinx Zynq SoCs for this (mainly the Zynq 7020 for 
> single drive emulation and the Zynq Ultrascale+ for up to 4 

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

Got me - I was thinking of HDDs which from the beginning had at least 2
heads so, given an appropriately sized Gap1,  it was always faster to switch
heads. 
And FWIW is some later SyQuest cartridge drives employing sectored servos it
was faster to seek than to switch heads so they made a head switch into a
seek, but they masked that all in the drive firmware

In any event, it really doesn't matter for this device emulator if the end
of a track is followed by a seek command; any time there is a seek command
there is lots of time for the device's housekeeping to get ready for the
next read.

Tom

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Wednesday, April 20, 2022 11:55 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: idea for a universal disk interface

On Wed, 20 Apr 2022, Tom Gardner via cctalk wrote:
> Likewise, I don't know it for certain, but I am pretty sure that it is 
> true that virtually all controllers switch heads sequentially when 
> transferring blocks beyond the end of the track,

Are you implying that data/file that is more than one track long has its
next data on a track that is a different head of the same cylinder?

If that is, indeed what you are saying, . . .
It would make sense, and is common.  Since it is obvious that switching
heads should take less time than stepping to the next cylinder.  BUT, it is
a choice by the file system, not by the controller.

As a simple example, when floppy disks went from single sided to double
sided, SOME OS programmers chose to switch heads before stepping to the 
next cylinder.   (Cylinder 0 side A, cylinder 0 side B, Cylinder 1 side A, 
cylinder 1 side B, etc.)

BUT, some chose to "keep what they had", and use the second side as an
"extension" of the first side, and chose to not switch heads until all
tracks on the first side were exhausted.  (Cylinder 0 side A, Cylinder 1
side A, Cylinder 2 side A . . . )  Of those, most "recalibrated" (seek to
zero) for the second side (cylinder 0 side A, Cylinder 1 side A . . .
Cylinder 75 side A, Cylinder 76 side A, Cylinde 0 side B, Cylinder 1 side B)
(that's for 77 track 8")  while others started using the second side
starting at the high end (to avoid the seek to zero delay).  (cylinder 0
side A, Cylinder 1 side A . . . Cylinder 75 side A, Cylinder 76 side A,
Cylinder 76 side B, cylinder 75 side B, . . .) There were a few more
variations, because it was the programmer making the decision, not the
controller, and we can come up with some amazing cockamamy ideas.

--
Grumpy Ol' Fred ci...@xenosoft.com

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

I don't know it for certain, but I am pretty sure that it is true that 
virtually all controllers issue the commands in this sequence, Set Cylinder, 
Set Head and then Seek, or words to that effect.
They then wait for Ready which can be 10's of milliseconds later. So there is 
plenty of time to load the whole track much less just the first few bytes after 
index sufficient to start a data transfer

Likewise, I don't know it for certain, but I am pretty sure that it is true 
that virtually all controllers switch heads sequentially when transferring 
blocks beyond the end of the track, so again, if necessary, those first blocks 
of the next track could be preloaded, but I am pretty sure that this is 
unnecessary, since there is more than a sufficient amount of time from the set 
head command to access the first block of bytes of the next track, sequential 
or not, after which the sustained data rate from memory far exceeds the clock 
rate to the controller

BTW, at the end of any real track is always a Gap4 for speed variation and 
truncation residue so there is a fair bit of time there for housekeeping too.

In other words, IMHO, a buffer on the order of a few memory words is more than 
enough

Tom


-Original Message-
From: shad [mailto:shado...@gmail.com] 
Sent: Tuesday, April 19, 2022 11:49 AM
To: cctalk@classiccmp.org
Subject: RE: idea for a universal disk interface

Guy,
I understand that cylinder command has no particular timing requirements, while 
head command must be effective within microseconds. My doubt is, RAM access on 
high performance port could be fast enough to satisfy also the latter.
In case it couldn't or was not assured, I think the best strategy could be to 
preload only a small block of data for each head, for prompt start on head 
command; enough to manage safely RAM access latency.
Each block also would work as buffer for data of subsequent RAM accesses, until 
whole cylinder had been processed.
This strategy would remove the strict requirement of blockram capacity for the 
Zynq, and given that bigger models cost a lot, it would be a significant spare 
for anybody.
Furthermore,� support for any hypotetical disk with bigger cylinder (not SMD) 
or for tape with very large blocks or "infinite" streams could not be feasible 
with the whole cylinder design. I would prefer to avoid any such limitation, in 
way to possibly reuse the same data transfer modules for any media.

Andrea

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

Agree that we are talking about two vastly different projects.

Personally I think the universal disk reader is doable and interesting but
expensive.

 

Start with a clean bench having an air bearing variable speed motor and a
universal mount to which various pack/cartridge adapters can be mounted.

Add a laser controlled horizontal positioner with a Z height adjustable
probe head station  (manual Z height at first but maybe automated if volume
dictates)

Add some sort of head load/unload

Pretty straight forward stuff

 

A modern TMR should easily read the much wider track of old iron oxide but
the issue is flying high and head crashes.  So there needs to be some
research here.  Perhaps a surface (or track) mechanical buffering process
would be sufficient or a ridiculously wide by current standards TMR head or
such a head with an adjustable flying height read element or some
combination should be workable.

 

Track following may or may not be a requirement.  If the read element is
small enough maybe just positioning it in the center is enough.  Or maybe
just once around synthetic run out compensation would work given the very
wide track/ very narrow reader.  If you have to go full track following
that's not much of a problem with the few embedded servo old iron but
implies a second head  reading the servo disk coupled to the reader head -
doable but one more head to crash and a whole research project on the
various track following systems and associated hardware.   Probably doable
with DSPs since the transition rate on the servo info is pretty low

 

Finally you get to interpreting the raw data; this might be relatively
straight forward since the data rate of old iron is fairly low so the analog
signal could be highly oversampled, 10x maybe, which makes the decoding
pretty straight forward if you know the format and recording code.

 

I once built a disk pack servo writer, class 100 clean room, slit the
concrete foundation, excavated and filled with sand, put an air bearing dc
motor with a 3330 spindle mount in a granite slab and used a laser
positioning micro stepping actuator to write the servo surface of 3336 class
disk packs.  Feels like a similar project

 

Tom 

 

 

 

 

-Original Message-
From: Paul Koning [mailto:paulkon...@comcast.net] 
Sent: Tuesday, April 19, 2022 5:30 AM
To: Mike Katz; cctalk@classiccmp.org
Subject: Re: idea for a universal disk interface

 

 

 

> On Apr 18, 2022, at 6:44 PM, Mike Katz via cctalk <
 cctalk@classiccmp.org> wrote:

> 

> Which is more generic.

> 

> ESDI, SMD or SCSI.

> 

> In my opinion, SCSI is as close are you are going to get to a universal
interface.

> 

> As for reading raw data from a drive.  The newer the drive, the higher the
bit density and lower the strength of the magnetic fields and hence the
lower the flying height.  You have to deal with linear (or horizontal)
recording, perpendicular recording, Heat assisted magnetic recording,
microwave assisted magnetic recording.  The latest technologies are
approaching 1TB (yes that's TB) per square inch.

> 

> If you spin the platters too slowly you will not be able to distinguish
individual magnetic fluctuations from noise.  What do you propose as your
maximum data density (in BPI) and what is the minimum speed you will need to
accurately decode it.

 

I know about some of the modern drive magic, but I wasn't talking about
those at all.  My comments about recovering raw signals from disk surfaces
is for much earlier disks, especially removable packs.  In more recent disks
you always have the drive if you have the disk since they are the same
thing.  (I'm ignoring "data recovery" services here that deal with
mechanically failed drives; that's a specialized business and as you said
it's increasingly difficult with modern drives.)  

 

If you consider 1960s through 1980s you're likely to run into disk packs for
which the drives may be hard to find.  The mechanical tolerances of those
devices require care but are not crazy difficult, as my RC11/RS64 example
last week was meant to illustrate.  The bit densities are not all that high,
nor the track densities.  Consider for example that the track positions on a
1311 drive are set by mechanical detents, and are low enough that no servo
system is used at all.

 

My mechanical skills and tools are perhaps a bit better than some of the
readers here, undoubtedly worse than others.  I could sketch a "spin table"
that could handle, say, an RK05 pack.  Without a milling machine I can't
build it, but that could be fixed, and I could refine my skills to make it
work.  Do I plan to?  No, but if an interesting enough pack showed up I
could imagine doing it.  The RA60 pack I have would be a bit more of a
stretch -- more platters and higher densities, not to mention lack of
documentation -- but it's still on the edge of possibilities.

 

So I think there are two different possible projects here.  One involves a
generic 

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

-Original Message-
From: Guy Sotomayor [mailto:g...@shiresoft.com] 
Sent: Friday, April 15, 2022 3:25 PM
To: t.gard...@computer.org; cct...@classiccmp.org
Subject: Re: idea for a universal disk interface

I'm looking at what the spec says.  ;-)  The read command delay from the head 
set command is 15us (so I was wrong) but still not a lot of time (that is after 
a head set, a read command must be at least 15us later).



-
And after the read command is given there is a gap, usually all zeros, at the 
end of which is a sync byte which is then followed by the first good data (or 
header) byte.  In SMD the gaps can be  20 or 30 bytes long so there is quite a 
bit of time until good data.

Tom

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

Not the RAMAC of 1956 but the RAMAC Virtual Array of 1996,
https://www.ibm.com/common/ssi/cgi-bin/ssialias?htmlfid=897/ENUSC96-029
type=AN=CA=skmwww 
It emulated several different IBM DASD of varying CKD track lengths on fixed
block HDDs

The trick they used and the one I'm suggesting is they stored an entire
track, index to index including, gaps, headers, etc, in a concatenated set
of fixed blocks greater than the maximum length of the raw track.

For example, an SMD drive turning at 3600 RPM and with a data rate of 15
Mb/sec and a 5% speed variation has a maximum track length of 31,250 bytes
nominally but never more than 32,895 on the slowest drive.  So allocating 65
sectors (512 byte) will fit the worst track.  Of course since the emulator
doesn't have any speed variation only 62 sectors need be allocated per
track.  

I poked around in some old Disk/Trends and it seems the largest ESDI/SMD
drive was on the order of 2.5 GB which is likely a formatted capacity so a
full drive emulation might require a maximum of 3.3 GB which is well within
the size of a modern PC and given the memory data rate I suspect an emulator
wouldn't have to buffer more than two memory words.

Tom



-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Friday, April 15, 2022 3:54 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: idea for a universal disk interface

On Thu, 14 Apr 2022, Tom Gardner via cctalk wrote:
> This was the approach IBM used in it's first RAMAC RAID where I think 
> they had to buffer a whole cylinder but that was many generations ago

(my copy of the specs may not be exact):
Buffering a whole cylinder, or a whole surface, of the RAMAC was no big
deal.
One hundred surfaces (52 platters, but not using bottom of bottommost nor
top of topmost) totalling to 5 million 6 bit characters.

That's 50,000 characters per surface.
OR 50,000 characters per cylinder
("square geometry" :-)

100 tracks per side of a platter (at 20 tracks per inch) meant about 500
characters per track

Problematic in the CP/M days, but such a buffer is small in current usage.

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

Interesting idea, there are three broad classes of HDD interfaces:

1.   Dumb, that is serial data and parallel control

2.   Intelligent parallel

3.   Intelligent serial

IMO if you can do dumb interraces then the others follow and given today’s 
technology I suspect it is feasible

Within the dumb group there are several “standards” with very similar controls 
but with different data rates and track formats

* 2311/2314 including PCM versions

* DEC RL0x which is pretty much the same as 2311/2314 except interface 
voltages and goes up to 200 MB disk pack drives, maybe higher

* Diablo which is a simplified control version of RL0x

* SMD which is an enhanced control version of RL0x

* ST502/412/412 RLL which is a simplified control version of RL0x

* ESDI which unfortunately serialized some of the control over the 
parallel interface otherwise similar to RL0x

There are a few others like ANSI and CalComp but they are probably not worth 
investigating.

 

 

I don’t know who invented the 1311 interface but IMHO he spawned an industry :)

 

I think the maximum data rate is something on the order of 15 MHz so one ought 
to be able to read in an entire track at a sufficiently high data rate so as to 
be able to decode the data  using an appropriately programmed DSP.  Essentially 
all the hardware used for serializing/deserializing, formatting/deformatting 
and ECC in a traditional controller reduced to firmware

 

Likewise there is a maximum number of control pins and only two voltage 
signaling levels (IBMs and DTL) so a combination of a programmable transceiver 
with a personality module ought to allow connection to and signaling with any 
physical device.  Communicating control and status then is also a programming 
exercise

 

Writing all the firmware would be a challenge but in the end you would be 
dealing with an array of blocks of good data, which would then be the starting 
point for tackling  the intelligent interfaces which purport to start and stop 
at the same array of blocks of good data.  I think u might be able to make this 
work with all the flavors of SCSI (with maybe a DSP on the personality module 
to handle the bus states) but good luck with intelligent serial interfaces.

 

Just my 2 cents :)

 

tom

 

 

 

-Original Message-
From: shad [mailto:shado...@gmail.com] 
Sent: Tuesday, April 12, 2022 10:36 PM
To: cct...@classiccmp.org  
Subject: idea for a universal disk interface

 

Hello,

I'm a decent collector of big iron, aka mini computers, mainly DEC and DG.

I'm often facing common problems with storage devices, magnetic discs and tapes 
are a little prone to give headaches after years, and replacement drives/media 
in case of a severe failure are unobtainable.

In some cases, the ability to make a dump of the media, also without a running 
computer is very important.

 

Whence the idea: realize an universal device, with several input/output 
interfaces, which could be used both as storage emulator, to run a computer 
without real storage, and as controller emulator, to read/write a media without 
a running computer.

To reduce costs as much as possible, and to allow the better compatibility, the 
main board shall host enough electrical interfaces to support a large number of 
disc standard interfaces, ideally by exchanging only a personality adapter for 
each specific interface, i.e. connectors and few components.

 

There are several orders of problems:

- electrical signals, number and type (most disk employ 5V TTL or 3.3V TTL, 
some interfaces use differential mode for some faster signals?)

- logical implementation: several electrical signals are used for a specific 
interface. These must be handled with correct timings

- software implementation: the universal device shall be able to switch between 
interface modes and be controlled by a remote PC

 

I suppose the only way to obtain this is to employ an FPGA for logic 
implementation of the interface, and a microprocessor running Linux to handle 
software management, data interchange to external (via Ethernet). This means a 
Xilinx Zynq module for instance.

I know there are several ready devices based on cheaper microcontrollers, but 
I'm sure these can't support fast and tight timing required by hard disk 
interfaces (SMD-E runs at 24MHz).

 

The main board should include a large enough array of bidirectional 
transceivers, possibly with variable voltage, to support as much interfaces as 
possible, namely at least Shugart floppy, ST506 MFM/RLL, ESDI, SMD, IDE, SCSI1, 
DEC DSSI, DEC RX01/02, DG6030, and so on, to give a starting point.

The common factor determining what kind of disc interface can be support on 
hardware side is obviously the type of transceiver employed, for instance a 
SATA would require a differential serial channel, which could not be available.

But most old electronic is based on TTL/CMOS 5V 

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

-Original Message-
From: ben [mailto:bfranc...@jetnet.ab.ca] 
Sent: Saturday, April 16, 2022 1:39 PM
To: cctalk@classiccmp.org
Subject: Re: idea for a universal disk interface

On 2022-04-16 1:13 p.m., Tom Gardner via cctalk wrote:
 
> Tom
> 
How do you handle the disk hardware timing, power up, seek and disk RPM?. Ben.


Those really shouldn't be any problem. 

RPM is data rate but unlike the disk drive the RPM and the data rate in an 
emulator are as precise as the crystal and hardware setting the data rate- no 
jitter, speed variation etc.  Everything is on time
The emulator would have to generate a synthetic Index signal (and sectors for 
hard sectored controllers) to keep the controller happy but that is just 
counting off a clock.

Power up - most drives tell the controller when they are ready but some have a 
start/stop controls.  Regardless, it is pretty easy for the emulator to respond 
to any commands and present appropriate status.  It doesn't have to wait for a 
disk pack to spin up - as soon as it gets a start command it can present ready 
status.

It would have to generate a home signal but all that means is the data pointer 
is pointing to the memory location of the first byte of the first track (Track 
00 head 00)

Seeks are near instantaneous - the controller issues the seek command and after 
a minimum delay the emulator presents ready status

The only thing the emulator really has to worry about is too quick responses 
breaking the controller

RE: idea for a universal disk interface

[Tom Gardner via cctalk]

Actually I am talking about emulating the bit stream, index to index - RLL 
encoded and containing gaps, marks, headers, data, CRC, ECC, etc.  Exactly as 
the bit stream would come out of a theoretical disk drive, no bit shift, no 
write splices, no instantaneous speed variation, no long term speed variation.  
That means the controller will have a very easy time of it.

My point is the ESDI/SME bit stream is 15 Mb/sec or lower and the others are 
lower still while any modern memory can transfer in the Gb/sec range so the 
track will arrive at the emulator hardware at much higher rate than the 
controller can absorb and since the track is coming from memory there is 
negligible latency.

You seem to assume that the transfer out of the emulator can't start until the 
entire track is in the emulator - that's not what I am saying.  To use your 
example, sure it takes 65us to transfer the entire track out of memory but it 
takes 16.67 msec to transfer it out of the emulator.   I suggest transfer out 
of the emulator hardware can start with the first word into it.

Tom

-Original Message-
From: Guy Sotomayor [mailto:g...@shiresoft.com] 
Sent: Saturday, April 16, 2022 5:14 PM
To: t.gard...@computer.org; cct...@classiccmp.org
Subject: Re: idea for a universal disk interface

I think the issue is that you're thinking of somehow emulating the formatted 
data.  I'm working on just emulating the bit-stream as then it'll work with any 
controller and sector/track layout so I won't actually know what a sector 
really is (unless I do "hard sectoring" 
which some drives did support).

At a 15Mhz clock rate, 30 bytes is 1.us.  Not a lot of time. And frankly, 
that's defined by the controller and not the drive (though usually the drives 
specify some layout but that's only a recommendation).  Dealing with drive 
speed variations doesn't solve anything because it's actually done via the 
drive itself (e.g. the drive provides the clock to the controller so any 
variation is already accounted for).  The drive really cares about total bits 
(e.g. 
bits-per-inch) that the media supports.

If we assume 32KB track at 500MB/s DMA transfer rate, that takes 65us.  But as 
I've said, the spec says that the time between a head select and read is 15us 
or so, you can see that you can't just transfer a track and still meet the 
minimum timings.  I will agree that you can probably take longer but I'm trying 
to have a design that can meet all of the minimum timings so I can emulate any 
drive/controller combination with at least the same performance as a real drive 
(and in many cases I can provide
*much* higher performance).

By keeping a full cylinder in the FPGA Block RAM I can keep the head select 
time < 1us (it's basically just selecting the high order address bits going to 
the block RAM).

By keeping the entire disk image in DRAM, I can emulate any drive (that fits in 
the DRAM) with identical (or faster) performance. If I wanted to do something 
simpler (not much though) I could have a smaller DRAM (but since the Zynq 
modules I'm using have 1GB or 4GB of DRAM there isn't much motivation) but then 
any seek would be limited by access to the backing store.  Also remember, in 
the worst case you have to write the previous track out if it was written to so 
that will slow things down as well.  With the full image maintained in DRAM, 
any writes can be performed in a lazy manner in the background so that won't 
impact the performance of the emulated drive.

TTFN - Guy

On 4/16/22 14:32, Tom Gardner wrote:
> -Original Message-
> From: Guy Sotomayor [mailto:g...@shiresoft.com]
> Sent: Friday, April 15, 2022 3:25 PM
> To: t.gard...@computer.org; cct...@classiccmp.org
> Subject: Re: idea for a universal disk interface
>
> I'm looking at what the spec says.  ;-)  The read command delay from the head 
> set command is 15us (so I was wrong) but still not a lot of time (that is 
> after a head set, a read command must be at least 15us later).
>
> 
>
> -
> And after the read command is given there is a gap, usually all zeros, at the 
> end of which is a sync byte which is then followed by the first good data (or 
> header) byte.  In SMD the gaps can be  20 or 30 bytes long so there is quite 
> a bit of time until good data.
>
> Tom
>
>
--
TTFN - Guy

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Tom Gardner via cctalk]

The only person who ever promulgated the "Dr. Wang bar napkin" story was Jim
Porter who was not in any way involved with the decision as to the size of
the 5½ drive or media size and only began telling his tale many years after
the decision.

 

Both Massaro and Adkisson deny there was ever such a meeting in a bar with
Dr. Wang.  

 

Some doubt Dr. Wang was ever in a bar with a vendor  :-)

 

My research suggests customers of Adkisson, e.g. Lanier, and not Wang Labs,
asked for a smaller and less expensive drive, with media about the size of a
cocktail napkin.

Adkisson took this request to SA management.  Wang was then their big
customer for 8-inch drives.

Massaro and Adkisson then did discuss this with Dr.  Wang who did express a
need for such a drive as a replacement; faster, more reliable and less
expensive than the 8-track tape drive used by Wang Labs. It was also
presented to Mohawk Data who was also interested.

 

Shugart engineering then sized the drive based upon a survey of the size of
8 track tape drives and then sized the media as what is the largest that
could reasonably fit within the drive envelope. The fact that the media size
is about the size of some cocktail napkins is a coincidence.

 

BTW as far as I can tell there is no standard size for cocktail napkins
circa 1976 and the one sample I found from that era is smaller than the
5¼-inch medium envelope.

 

The corruption of history is indeed tragic both here and at the Smithsonian
- BTW, I did send their webmaster a request for correction

 

Tom

 

 

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Saturday, August 20, 2022 3:37 PM
To: dwight via cctalk
Subject: [cctalk] Re: "Revival" of a dedicated Micropolis webpage on
internet

 

Adkisson and Masaro now deny the whole "bar napkin disk" story; In agreement
that 8" was larger than desired, they asked Dr. Au Wang "What size should it
be?"

Wang picked up the bar napkin (the meeting was not in a conference room),
and said, "This size".

They took the napkin back to the lab and measured it.

 

and the Smithsonian says that SA400 was 3.25".

 

Yes, the loss of our history is just tragic.

 

 

On Sat, 20 Aug 2022, dwight via cctalk wrote:

 

> Maybe it is on a size reduction.

> Dwight

> 

> 

> From: geneb via cctalk < 
cctalk@classiccmp.org>

> Sent: Saturday, August 20, 2022 7:47 AM

> To: Liam Proven via cctalk < 
cctalk@classiccmp.org>

> Cc: geneb <  ge...@deltasoft.com>

> Subject: [cctalk] Re: "Revival" of a dedicated Micropolis webpage on 

> internet

> 

> On Wed, 17 Aug 2022, Liam Proven via cctalk wrote:

> 

>> On Tue, 16 Aug 2022 at 23:51, Fred Cisin via cctalk 

>> <  cctalk@classiccmp.org> wrote:

>>> 

>>> 1) because they need to keep reinforcing until the very last SA400 

>>> is buried.

>>> 

> 

> Fred, Don't forget the SA390 in every Disk II. ;)

> 

>> I had to look up SA400. I'm too young.

>> 

>> The Smithsonian has one. They say it's a 3¼ inch drive.

>> 

>>  
https://www.si.edu/object/microcomputer-peripheral-shugart-sa400-disk

>> -drive:nmah_334325

>> 

> 

> Now THAT is just tragic.

> 

> g.

> 

> --

> Proud owner of F-15C 80-0007

>   http://www.f15sim.com - The only one of its kind.

>   http://www.diy-cockpits.org/coll - Go
Collimated or Go Home.

> Some people collect things for a hobby.  Geeks collect hobbies.

> 

> ScarletDME - The red hot Data Management Environment A Multi-Value 

> database for the masses, not the classes.

>   http://scarlet.deltasoft.com - Get it
_today_!

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Tom Gardner via cctalk]

Sorry, there was no “U” consideration in the FH 5¼-inch form factor
decision. It is 5.75 in × 3.25 in × 8 in; none of these have integer "U"
relationships.

 

SA engineering studied the various 8-track tape drives then available and
found no standard form factor so they picked a set of numbers that they
thought would work for most and for the Wang application in particular.  No
one mentioned “U” dimensions as a consideration.

 

I seem to recall most 8-track tape drives were mounted horizontally which
would make the “U” height 3.5-inches not 3.25 inches.

 

 

 

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Sunday, August 21, 2022 5:40 PM
To: General Discussion: On-Topic and Off-Topic Posts
Cc: t.gard...@computer.org; Tom Gardner
Subject: RE: [cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a
dedicated Micropolis webpage on internet]

 

On Mon, 22 Aug 2022, W2HX wrote:

> I always thought it was interesting how 5 1/4 is 3U (rack units). I 

> thought there might have been some relationship to that. But could 

> have been just coincidence.

 

I think that it is related.

I think that the drive (not the diskette) was apparently intended to be
mountable where certain tape drives were mounted.

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Tom Gardner via cctalk]

>-Original Message-
>From: Fred Cisin [mailto:ci...@xenosoft.com] 
>Sent: Sunday, August 21, 2022 12:31 PM
>To: General Discussion: On-Topic and Off-Topic Posts
>Subject: [cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a
dedicated Micropolis webpage on internet]

 

>On Sun, 21 Aug 2022, Tom Gardner via cctalk wrote:

> The only person who ever promulgated the "Dr. Wang bar napkin" story 

> was Jim Porter who was not in any way involved with the decision as to 

> the size of the 5½ drive or media size and only began telling his tale 

> many years after the decision.

> Both Massaro and Adkisson deny there was ever such a meeting in a bar 

> with Dr. Wang.





>In

>
<http://archive.computerhistory.org/resources/text/Oral_History/5.25_3.5_Flo
ppy_Drive/5.25_and_3.5_Floppy_Panel.oral_history.2005.102657925.pdf>
http://archive.computerhistory.org/resources/text/Oral_History/5.25_3.5_Flop
py_Drive/5.25_and_3.5_Floppy_Panel.oral_history.2005.102657925.pdf

>Jim Porter attributes it to Jimmy Adkisson.

 

If you read further on you will find that Adkisson also has disclaimed the
Porter fable. 

 

FWIW, Porter apparently began promulgating the fable in 1998  at his speech
to 100th Anniversary Of Magnetic Recording, Santa Clara University, Santa
Clara, CA. 

http://web.archive.org/web/20071014221838/http://magneticdiskheritagecenter.
org/100th/Progress/Porter/jimporter.htm
<http://web.archive.org/web/20071014221838/http:/magneticdiskheritagecenter.
org/100th/Progress/Porter/jimporter.htm> . 

There is no earlier reference that I can find. 

 

I talked to the entire Shugart Associates team (including both Massaro and
Adkisson) involved in the decision to do the 5¼ and its design thereafter -
the Wang story is BS

 



 

 

>But, Massaro, who should know, refutes the story.  Although his version is
about a cardboard mockup of the DRIVE, done in the backseat of a car, NOT
the origin of the diskette size.

>Grumpy Ol' Fred <mailto:ci...@xenosoft.com>
ci...@xenosoft.com

 

Tom

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Tom Gardner via cctalk]

Fred:

Please quote the current version of the oral history,

It says:

 

Porter: Jimmy said that you guys got together with the guys at Wang in a
dark bar one night and, after a 

discussion, you decided on the size of what the smaller diskette should be
and there was a cocktail napkin 

on the bar which was 5 1/4" square  napkin . That's
Jimmy's story.

 

[Ed. note: Contacted in 2009, both Adkisson and Massaro stated that there
was never any such meeting 

in a bar with Dr. Wang]

 

5.25 and 3.5 Floppy Disk Oral History Panel (computerhistory.org)
  at page 10

 

Will you now stop promulgating this fable?

 

Tom

 

 

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Sunday, August 21, 2022 3:34 PM
To: Fred Cisin via cctalk
Subject: [cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a
dedicated Micropolis webpage on internet]

 

BTW, I first heard the story in the late 1980s?  My recollection was that it
was in a sidebar in a magazine article.  I can't currently find that.

 

Massaro's denial of it

 

http://archive.computerhistory.org/resources/text/Oral_History/5.25_3.5_Flop
py_Drive/5.25_and_3.5_Floppy_Panel.oral_history.2005.102657925.pdf

was 2006?

 

 

The story was about the diskette size.

Massaro's story is about the size of the DRIVE, and making a cardboard
mockup in the backseat of a car.

 

Unless Adkisson comes forward, and reasserts the validity of the story, then
it is unlikely.

 

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Tom Gardner via cctalk]

That's one of the "features" of the CHM oral history archives, they keep
older versions on line on "scholarly" principles.
I've suggest they keep only the current version on line and include a change
log to no avail
Tom

-Original Message-
From: Fred Cisin [mailto:ci...@xenosoft.com] 
Sent: Sunday, August 21, 2022 11:32 PM
To: t.gard...@computer.org
Cc: 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: [cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a
dedicated Micropolis webpage on internet]

On Sun, 21 Aug 2022, Tom Gardner wrote:
> Fred:
> Please quote the current version of the oral history, It says:
> Porter: Jimmy said that you guys got together with the guys at Wang in 
> a dark bar one night and, after a discussion, you decided on the size 
> of what the smaller diskette should be and there was a cocktail napkin 
> on the bar which was 5 1/4" square  napkin . 
> That's Jimmy's story.
> [Ed. note: Contacted in 2009, both Adkisson and Massaro stated that 
> there was never any such meeting in a bar with Dr. Wang]
> 5.25 and 3.5 Floppy Disk Oral History Panel (computerhistory.org)
>  657925
> -05-01-acc.pdf>  at page 10
> Will you now stop promulgating this fable?

Yes.  Knowing that BOTH deny it shows that it is an apocryphal tale.
I was, indeed, looking at an older version (2005) When I had only heard of
Massaro's refutation, I was wondering whether Adkisson agreed.  Now, it is
clear.
Thank you.

[cctalk] Re: Floppy Disk Drive Controller History

[Tom Gardner via cctalk]

WD was first and its line of FDCs with compatible suppliers competed with 
NEC/INTEL's line, see https://en.wikipedia.org/wiki/Western_Digital_FD1771 

 

The IBM PC's usage of the uPD765 gave prominence to the NEC/Intel line.  

 

At this point I can't really say which if either came to dominate the market 
but in the end the function wound up in the "southbridge" and then pretty much 
disappeared. 

I suspect NEC/Intel might have won - the Microchip (SMSC) FDC37C78 was one of 
the last if not last chip in production - it was a "Licensed CMOS 765B Floppy 
Disk Controller" and may have been in production as late as 2013

 

There are lots of chips for sale on the Internet but they look to me to be 
salvaged or surplus chips - does anyone know of chips in current production?

Was Microchip/SMSC the last (Microchip acquired SMSC in 2012)?

Some other late chips with dates from documents:

* Toshiba TC8569AF 1989?

* Hynix GM82C765B

* Intel 82078 1996?

 

Tom

 

-Original Message-
From: Chuck Guzis [mailto:ccl...@sydex.com] 
Sent: Saturday, September 03, 2022 8:47 AM
To: jim stephens via cctalk
Subject: [cctalk] Re: Floppy Disk Drive Controller History

 

On 9/3/22 02:07, jim stephens via cctalk wrote:

 

> I hope you get information on Don Tarbell's work included.  He had an 

> early single density controller.  Then later a high (double) density 

> controller.

 

I purchased Don's SD controller way back when--and assembled it myself.

I still have it, and his manual.

 

I got it to replace the 2-board IMSAI controller that used an NEC 8080A.

That board was far from reliable.

 

Don's controller used the WD1771, so I don't know what that has to do with 
Intel and NEC.

 

--Chuck

[cctalk] Floppy disks for sale [WAS:RE: cctalk Digest, Vol 97, Issue 35]

[Tom Gardner via cctalk]

Tom Persky at https://www.floppydisk.com/ sells all types of FDs, albeit
well above the AOL price :-)

Interesting article about this last man standing in the business:
https://eyeondesign.aiga.org/we-spoke-with-the-last-person-standing-in-the-f
loppy-disk-business/#:~:text=Tom%20Persky%20is%20the%20self,and%20recycling%
20of%20floppy%20disks. 

BTW, there are still four companies making iron oxide tape, but just
currently for audio/video/instrument usage.  
If the demand for FDs continues past  Tom's inventory then I wouldn't be
surprised to see one of them make some FDs too.

Tom

-Original Message-
From: cctalk-requ...@classiccmp.org [mailto:cctalk-requ...@classiccmp.org] 
Sent: Friday, October 14, 2022 10:00 AM
To: cctalk@classiccmp.org
Subject: cctalk Digest, Vol 97, Issue 35

Send cctalk mailing list submissions to
cctalk@classiccmp.org

To subscribe or unsubscribe via email, send a message with subject or body
'help' to
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You can reach the person managing the list at
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When replying, please edit your Subject line so it is more specific than
"Re: Contents of cctalk digest..."

[cctalk] Floppy Disk Drive Controller History

[Tom Gardner via cctalk]

I’m working on an update to Wikipedia on floppy disk drive controllers –
there is a nice section on WD but nothing on Intel/NEC

 

Anyone know the history of how the NEC µPD765 and the Intel 8272 became
compatible devices?

 

AFAICT it was IBM's August 1981 adoption of the NEC µPD765 in the PC that
drove the industry to standardize on the device.

 

The earliest dates I can find for the two devices are:

 


Jan 1981

8272 listed in Intel catalog (not in 1979 catalog)


1979

µPD765 listed in NEC catalog
 


Dec 1978

µPD765 Data Sheet
 

 

As described in the 1978 data sheet the NEC device was 8-inch FD compatible
and of course the PC used 5¼-inch drives but I suspect the differences could
be worked around

 

It may well be that they were compatible in previous versions (µPD372 and
8271)

 

Any recollections and links would be appreciated

 

Tom

 

[cctalk] Re: Age of Tape Formats?

[Tom Gardner via cctalk]

If you want authoritative sources I highly recommend:

*IBM J. RES. DEVELOP. • VOL. 25 • NO. 5 • SEPTEMBER 1981, has an 
article “Innovations in the Design of Magnetic Tape Subsystems”

*IBM Journal of Research and Development Vol. 47, No. 4, July 2003 has 
an article “Fifty years of IBM innovation with information storage on magnetic 
tape”

*Magnetic Recording, the First 100 Years, Daniel et al, Chapter 17, 
Data Storage On Tape

*Magnetic Recording, Vol II: Computer Data Storage, Mee et al, Chapter 
4 Data Storage

*The Complete Handbook of Magnetic Recording, Jorgensen, Parts 4 and 5 
which deal with tape materials and transports

The first ref above gives the date of IBM’s shipment of 6250 bpi as 1973, AFAIK 
that became the industry standard for ½ r-t-r tape

I have all of the above in my library and might be able to help u off line if 
you have specific questions.

 

I’ve worked on tape articles in Wikipedia and they are for the most part pretty 
good.  If u find any errors or omissions I hope u will update

 

If you are willing and able to share I’d like to see yr results

 

Good luck

 

Tom

 

 

-Original Message-
From: Zane Healy [mailto:heal...@avanthar.com] 
Sent: Tuesday, March 07, 2023 5:05 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: [cctalk] Age of Tape Formats?

 

I�m working on a project, and I need to know the age of various tape formats.  
For example when were 6250bpi 700� 9-Track tapes or DC600A cartridges 
introduced?  Is there any good resource online that documents this?  Wikipedia 
is of some help, but the older you go, the spottier it is.

 

Zane

 

 

 

[cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?

[Tom Gardner via cctalk]

Well the data are still there and could be retrieved with a sophisticated servo 
on data system and/or a probe head on the data surfaces.
Simpler to hit the spindle motor top dead center with a very large hammer 
ruining the bearings and crashing a few heads in the process.
Even then the data are still there so nothing beats a multi-pass full disk wipe

-Original Message-
From: Chris Zach [mailto:c...@beaker.crystel.com] 
Sent: Thursday, March 23, 2023 9:53 AM
To: cctalk@classiccmp.org
Subject: [cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?

Speaking from experience with an old RD54, yep. Put a magnet on the outside 
case towards the bottom, spin the drive up and it's gone forever.

On 3/23/2023 12:22 PM, Daniel Daigle via cctalk wrote:
> Old MFM/RLL drives with stepper positioners generally have no servo. 
> The same can't be said of voice-coil positioned drives; they could use 
> any means, including hardware optical servos, etc. but often used a 
> surface and a head for that purpose... so yes, you can render one of 
> these drives useless with a magnet if yours has a servo surface. (This 
> is not the same as embedded servo, which places servo information 
> -with- the data on the same surfaces.)

[cctalk] Re: ST512 [WAS:RE: Re: Nuking an MFM drive with a magnet, format/servo gone?]

[Tom Gardner via cctalk]

The ST512 was a thin-film head version of the ST506, per Seagate : 
"This increased capacity is accomplished by using the inner portion of the disc 
surface that was previously unused and by increasing the disc track density 
from 255 tracks per inch to 270 tracks per inch To reliably use the inner 
portion of the disc. The ST512 uses a new type of read/write head - a "thin 
film" head."

It was dropped in 1981 due to the lack of a reliable supply of heads and 
replaced by the ST412.

-Original Message-
From: Tony Duell [mailto:ard.p850...@gmail.com] 
Sent: Friday, February 03, 2023 9:27 AM
To: Alexandre Souza
Cc: General Discussion: On-Topic and Off-Topic Posts
Subject: [cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?

On Fri, Feb 3, 2023 at 5:21 PM Alexandre Souza  
wrote:
>
> I thoug the right one was st512...can you enlighten me on this subject Tony?

I've never heard it called that.

It's often called 'ST506' but that drive had a few differences from the later 
ones. it didn't support buffered seeks AFAIK. The ST412 did and was the most 
common of a family of 3 similar drives (ST406, ST412,
ST419) so it tends to be used as the de-facto name of the interface.

-tony

[cctalk] Re: First non-IBM PC-DOS Compatible PC

[Tom Gardner via cctalk]

Chuck: Thanks but AFAICT the Columbia MPC-1600 was not PC-DOS compatible

 

MS-DOS and PC-DOS

Because PC-DOS and MS-DOS share the same origins, the quest for a compatible 
operating system isn’t formidable. To successfully emulate PC-DOS, we at 
Columbia Data Products (CDP) provided a second BIOS and modified the MS-DOS 
source code. MS-DOS requires its own BIOS to provide a well-defined interface 
between the operating system and the hardware and peripherals. On the PC or a 
compatible, however, the PC MS-DOS BIOS uses the ROM BIOS and its existing 
low-level drivers. Therefore, the machine independent part of MS-DOS resides in 
RAM with the tailored MS-DOS BIOS. The resulting operating system behaves like 
PC-DOS. Because the same level of documentation is not made available for the 
PC-DOS BIOS

Technical Aspects of IBM PC Compatibility

Byte November 1983

This article was written by staffers at Columbia Data Products Inc.

https://archive.org/stream/byte-magazine-1983-11/1983_11_BYTE_08-11_Inside_the_IBM_PC#page/n249/mode/2up
 

 

Apparently Columbia like Compaq did independently develop their BIOS but with 
the objective of MS-DOS compatibility and a I think a proprietary version 
thereof.

And the article referenced says they both did a very good job

This is also confirmed at History - Who were the first engineers to  
<https://retrocomputing.stackexchange.com/questions/5855/who-were-the-first-engineers-to-cleanroom-the-ibm-pc-bios>
 "cleanroom" the IBM PC BIOS? - Retrocomputing Stack Exchange

 

I seem to recall the critical tests were some games that made extensive use of 
the IBM PC video BIOS calls.

 

Still looks like Phoenix or Tandon as the first with a PC-DOS compatible BIOS

 

Tom

 

-Original Message-
From: Chuck Guzis  
Sent: Monday, June 05, 2023 11:03 PM
To: Tom Gardner via cctalk 
Subject: [cctalk] Re: First non-IBM PC-DOS Compatible PC

 

On 6/5/23 22:28, Tom Gardner via cctalk wrote:

 

> Can anyone identify a PC-DOS compatible PC announced earlier than October 
> 1984?  Citations would be greatly  appreciated.

 

That's a tricky one,I think. For example, if a single programmer read the IBM 
PC BIOS listing (or even disassembled it) and then wrote a new one from 
scratch, that derivative BIOS in the view of the IBM legal beagles would not 
have been legal.

 

If, on the other hand, the same programmer never saw any of the code, but read 
the API description and wrote a BIOS, that would be legal.

 

Both ERSO and Phoenix resorted to a "clean room" method where one team read the 
PC BIOS and wrote a description, which served as a specification for a 
derivative BIOS.  I think that the descriptions were cleaned up a bit and 
published as the Phoenix BIOS books.

 

But I think the first "clean room BIOS" was in the Columbia MPC-1600, June 1982.

 

--Chuck

 

 

[cctalk] First non-IBM PC-DOS Compatible PC

[Tom Gardner via cctalk]

Hi:

 

Doing some research for historical purposed – no litigation at all – trying to 
identify the first “legal” PC-DOS compatible PC, “legal” in the sense that it’s 
BIOS was not a copy of an IBM BIOS.  Eagle gets the honor of being first MS-DOS 
compatible and getting sued for copying IBM’s BIOS 

 

The Compaq Portable which shipped in November 1982 is generally credited with 
the first legal MS-DOS compatible PC.  AFAIK it could not run PC-DOS and those 
applications which depended upon certain IBM BIOS commands would fail.

 

The first “legal” BIOS is generally considered to be from Phoenix which was 
announced in May 1984 and so far I have been unable to determine its first 
system deployments.  FWIW Wikipedia points to HP, Tandy and AT as some time 
adopters of a Phoenix BIOS but my research so far is that Tandy’s T1000 family 
announced in October and November of 1984 was the first system to be PC-DOS 
compatible and it did not use a Phoenix BIOS!  Such PC-DOS compatible HP and 
AT systems were much later and the Tandy BIOS was written by programmers of 
Tandon Corporation, the OEM supplier of the first Tandy T1000s.

 

Can anyone identify a PC-DOS compatible PC announced earlier than October 1984? 
 Citations would be greatly  appreciated.

 

Thanks

 

Tom

[cctalk] Re: The MAC at 40

[Tom Gardner via cctalk]

 

 

-Original Message-

From: Sellam Abraham  
Sent: Wednesday, January 24, 2024 2:16 PM
To: General Discussion: On-Topic and Off-Topic Posts 
Subject: [cctalk] Re: The MAC at 40

 

On Wed, Jan 24, 2024 at 2:04 PM Andrew Diller via cctalk <  
 cctalk@classiccmp.org> wrote:

 

 That 

> story of "stolen from PARC" IMHO is just weak writing back when the 

> Internet didn't have the info it has today which gives full context over what 
> was going on.



 

I read a narrative more recently that more accurately depicted the actual 
events.  I wish I could remember any details about it, otherwise I would link 
it up so others could read it.

 

But basically, Jobs never stole anything.  He was pretty much invited to take a 
look, and then entered into some sort of exclusivity deal (I may be wrong about 
this detail) to use Xerox tech.  Xerox upper execs didn't see a market in this 
kind of hardware; copiers were their game, so they didn't get what they had, 
and didn't care.  If anything, Apple should be thanked for taking what would 
have been deadend technology at Xerox and making a product with it.  Basically.

 

Sellam

Xerox was a pre-IPO investor in Apple and Xerox Development Corp (XDC) is 
reported to have granted Jobs visits to PARC in December 1979.  Jes Raskin 
claims to have also facilitated at least one visit after the investment.

 

What is not well known is Jobs had a visit to PARC prior to the Xerox 
investment which was conducted by the President of Shugart Corporation, then a 
subsidiary of Xerox.  Jobs had offered pre-IPO stock to the Shugart executives, 
but when they requested advice from XDC as to whether it was OK, XDC took on 
the investment.   Apple was then Shugart’s largest customer and needing to kill 
some time before a meeting Shugart’s President, Don Massaro, took Jobs thru 
PARC where Jobs purportedly first viewed the various technologies.  It is lost 
to history what sort of disclosure agreements existed at that time between 
Apple and Shugart Corp.

 

Tom

[cctalk] IBM 350 disk and 305 drum [WAS:RE: Re: Drum memory on pdp11's? Wikipedia thinks so....]

[Tom Gardner via cctalk]

The IBM 350 disk storage (RAMAC) has 5 million 6-bit characters or 3.75 MB; the 
actual recorded characters were 8-bits in length including a parity bit and a 
stop bit for each recorded 6-bit character

 

It was announced as part of the IBM 305 RAMAC system which had drum memory 
which as far as I can tell had 24 tracks of 100 6-bit characters = 14,400 bits 
or 1.8 kB

Source: 
http://bitsavers.trailing-edge.com/pdf/ibm/305_ramac/22-6264-1_305_RAMAC_Manual_of_Operation_Apr57.pdf
  pgs 17 &18

If anyone has a better number please post it 

 

Tom

 

-Original Message-
From: Mike Katz  
Sent: Monday, April 15, 2024 9:33 AM
To: General Discussion: On-Topic and Off-Topic Posts 
Cc: Douglas Taylor 
Subject: [cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so

 

There was drum storage for the early PDP-8 the "Straight 8", PDP-9 and PDP-10.  
Each drum stored 32,768 words.  Up to 8 of them could be connected for a total 
storage of 262,144 words of storage.

 

IBM made a 5BM drum storage unit that was the side of a small

refrigerator: The RAMAC's disk storage unit, the IBM 350, weighed over a ton, 
had to be moved around with forklifts, and was delivered via large cargo 
airplanes. It stored approximately 5MB of data: *five million 8-bit characters 
on fifty 24-inch-diameter disks*, a form of drum memory.

 

[cctalk] Re: IBM 360

[Tom Gardner via cctalk]

Data Cell - Tape, Card or Disk?

I'm pretty sure the developers thought of the  media of the IBM 2321 as tape
rather than cards, although the strips (of tape) were addressed as disk
drives (DASD) not tape.  It was a mechanical marvel that IMO then (late 60s)
only IBM could have successfully built and marketed such a beast.  Those
interested might want to read the oral history on this machine at
https://archive.computerhistory.org/resources/access/text/2013/05/102657934-
05-01-acc.pdf  My favorite failure was when they found strips back in the
bins but up-side down and backwards - they fixed than and many other
problems too and in the end I'm told it was a rather successful product.

NCR CRAM (Card Random Access Memory) truly considered magnetic cards as the
media, see
https://www.computerhistory.org/brochures/m-p/national-cash-register-company
-ncr/ 

Tom

-Original Message-
From: Paul Koning  
Sent: Friday, April 12, 2024 6:54 AM
To: cctalk@classiccmp.org
Subject: [cctalk] Re: IBM 360



> On Apr 12, 2024, at 9:48 AM, Liam Proven via cctalk
 wrote:
> 
> On Fri, 12 Apr 2024 at 13:31, Paul Koning  wrote:
> 
>> Yes.  See also https://en.wikipedia.org/wiki/IBM_2321_Data_Cell .  By the
standards of the time it was an unusually high capacity storage device, way
faster than a room full of tapes and much larger than the 2311 disk drive.
> 
> Fascinating. Thank you. It sounds truly awful. A device that 
> effectively tries to push strips of tape into receptacles?

I suppose.  Or magnetic cards.  There were other devices that used magnetic
cards, like the Olivetti Programma -- world's first programmable calculator.
For that matter, magnetic cards are still around, they are called credit
cards.  :-)

paul

[cctalk] Re: IBM 360

[Tom Gardner via cctalk]

When I said "addressed as disk drives (DASD)" I was referring to IBM's
DASD's (Direct Access Storage Device's) CKD (Count Key Data)  format
introduced with the System/360  which supported variable length records, or
as Paul calls them "variable length sectors" on disk drives, data cells and
drums amongst other devices. The Count field of each Record defined the
length of both the optional Key field the Data field so that on a single
track you could have records of different length - not likely but possible.
It was also possible to write a record longer than a track using record
overflow.

Variable length CKD records are still supported today in IBM's mainframe
systems by emulation on arrays of fixed sector HDDs.  

Tom

-Original Message-
From: Paul Koning  
Sent: Friday, April 12, 2024 12:13 PM
To: t.gard...@computer.org; cctalk@classiccmp.org
Cc: Tom Gardner 
Subject: Re: [cctalk] IBM 360



> On Apr 12, 2024, at 2:10 PM, Tom Gardner via cctalk
 wrote:
> 
> Data Cell - Tape, Card or Disk?
> 
> I'm pretty sure the developers thought of the  media of the IBM 2321 
> as tape rather than cards, although the strips (of tape) were 
> addressed as disk drives (DASD) not tape.

Actually, they look like a disk.  See the 2841 manual on Bitsavers (that's
the controller which drives 2311 disks as well as 2321 data cell devices).
It says that each strip has 100 tracks, read/written by a movable heads unit
that has 20 heads on it, so 5 positions.  And it shows the layout of each
track, which is the conventions count/key/data layout of 360 disk drives
like the 2311.  Yes, variable length "sectors", you'd specify in the JCL
what you wanted for blocksize of that particular file.  If I remember right,
the block length could vary from one block to the next, which is pretty
wild.  (Contrast with the EL-X8 disk drive, which also has variable length
sectors, but more limited: a choice of one of 5 possible sizes, chosen on a
per-track basis when you first write or format that track.)  Apart from
those, I only ever remember seeing fixed size sectors, though the actual
lengths might be strange -- like the CDC mainframe disks with sectors of 322
12-bit words.

paul

[cctalk] Re: PCs in home vs businesses (70s/80s)

[Tom Gardner via cctalk]

Interesting discussion, but don't forget software was free until on June 23, 
1969, when IBM announced its unbundled offerings!  The computer manufacturers 
then separately priced their software but at it is what sold the hardware for 
some time thereafter.

It was, for quite some time, always safe for business to buy IBM, regardless of 
price.

But the 1970s represented a transition period when independent software vendors 
starting selling software for specific machines but then thanks to Unix (?) 
across hardware.  There were plug compatible computers for IBM and even DEC.  
The price of the hardware was such that this was business oriented commerce and 
I think hardware drove the sales, but with specific software sometimes being a 
requirement for a specific application.  

The advent of personal computers in the late 70s made computing available to 
the home but I'm not sure whether the impulse to buy was the hardware, Apple v 
IBM. or software, possibly games or more likely software one needed at home for 
work purposes, WordPress, VisiCalc, etc

And the plug compatible PCs changed the market all again.

Tom

-Original Message-
From: Tarek Hoteit  
Sent: Saturday, April 27, 2024 10:16 AM
To: cctalk@classiccmp.org
Subject: [cctalk] PCs in home vs businesses (70s/80s)

I came across this paragraph from the July 1981 Popular Science magazine 
edition in the article titled “Compute power - pro models at almost home-unit 
prices.” 

“ ‘Personal-computer buffs may buy a machine, bring it home, and then spend the 
rest of their time looking for things it can do’, said …. ‘In business, it’s 
the other way around. Here you know the job, you have to find a machine that 
will do it. More precisely, you have to find software that will do the job. 
Finding a computer to use the software you’ve selected becomes secondary.”. 

Do you guys* think that software drove hardware sales rather than the other way 
around for businesses in the early days? I recall that computer hardware 
salespeople would be knocking on businesses office doors rather than software 
salesmen.  Just seeking your opinion now that we are far ahead from 1981. 

 (*I do wish we have female gender engaged in the classic computing discussions 
threads as well. Maybe there is.) 

Regards,
Tarek Hoteit
AI Consultant, PhD
+1 360-838-3675