[cctalk] Re: Double Density 3.5" Floppy Disks

[Joshua Rice via cctalk]

I can't vouch for later drives, but the earliest 600RPM Sony drives were 
built we no knowledge of HD vs DD, so covering the HD hole is probably a 
moot point in the HP drives, though it is likely worth taping over it 
for any formatting options.


It's worth noting that the speed is pretty much a moot point as well. As 
long as the data is written on the disks correctly by the modern 
machine, the older 600RPM drives should have no problem reading it. My 
RCA MS2000 reads floppies written in modern machines perfectly fine and 
that has even more oddball single sided 600RPM drives.


As someone else said, the disk loading mechanism gets very stiff as the 
lubricant solidifies. It's quite easy to free it up with some IPA and 
patience. I'd be very careful not to ruin the upper heads on dual sided 
drives by forcing disks in and out though. Thankfully a moot point with 
my drives!


Could be that the drive heads need cleaning and alignment. Have you had 
any success formatting disks on the target machine, if possible?


Josh Rice

On 30/04/2024 21:06, Mike Katz via cctalk wrote:
Thank you for trying to help.  My situation is unusual at best and I'm 
apologize for the extra bandwidth my question is causing.


*snip*

The HP9114A drive uses a modified Sony 3.5" floppy drive running at 
600 RPM instead of the normal 300 RPM.  This is an extremely unusual 
configuration that is different from any PC/MAC/Commodore/Amiga 
situation.


*snip*

Than you again everyone for offering to help,

  Mike

On 4/30/2024 2:41 PM, Wayne S wrote:

What errors are you seeing?


Sent from my iPhone

On Apr 30, 2024, at 12:29, Mike Katz via cctalk 
 wrote:


I have tried bulk erasing 1.44 MB disks and they still won't format 
in the HP9114A battery operated HP-IL Floppy Disk drive.



On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote:

On 30/04/2024 18:08, Anders Nelson via cctalk wrote:

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?
I think it's entirely possible. I'd definitely format them in a 
720kb drive though to be extra safe. Though original 720KB disks 
written/formatted  in 1.44MB drives seem perfectly cromulent from 
my experience.


However don't quote me on it, The only double density drives i have 
are super early Sony ones built in 1982 and they get pampered with 
NOS 720kb media (with the sliders sellotaped open because no auto 
opening shutters on my drives!)


Josh Rice

[cctalk] Re: Double Density 3.5" Floppy Disks

[Joshua Rice via cctalk]

On 30/04/2024 18:08, Anders Nelson via cctalk wrote:


Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?


I think it's entirely possible. I'd definitely format them in a 720kb 
drive though to be extra safe. Though original 720KB disks 
written/formatted  in 1.44MB drives seem perfectly cromulent from my 
experience.


However don't quote me on it, The only double density drives i have are 
super early Sony ones built in 1982 and they get pampered with NOS 720kb 
media (with the sliders sellotaped open because no auto opening shutters 
on my drives!)


Josh Rice

[cctalk] Re: PCs in home vs businesses (70s/80s)

[Joshua Rice via cctalk]

I'm a youngster when it comes to this hobby, being manufactured myself 
in the early years of the 90's. As such i cannot really quote from my 
experiences "at the time", but i have spent many an hour tinkering with 
old machines and researching for this vintage (and modern) computing 
hobby of mine, as well as working with some modern enterprise gear that 
makes me, in some ways, probably quite well versed in this sort of subject.


The demands for software and hardware definitely differ greatly between 
business requirements and home user requirements. Businesses have always 
had strict needs that must be fulfilled by the hardware they purchase, 
namely performing the operations they require. In the "early days", this 
might have been payroll tasks, document processing, inventory, computer 
aided manufacturing etc. Software to perform such tasks was often 
developed "in house", especially in the 60's, and the demands from the 
software would often dictate what hardware was required. Remember, 
computers were (and in some senses still are) expensive bits of kit, and 
savings should be made where possible. Sure, you could use an IBM 
System/360 to do manufacturing automation, but it would be much more 
cost effective to use a PDP-8, PDP-11, or DG Nova. On the flip side, 
that PDP-8 is not going to have the hardware support or speed to handle 
large volumes of ASCII characters to run a flight booking system for a 
major airline. You purchase the hardware that runs the software you 
require. Of course, in the later years of the "early days", more 
software was available "off the shelf", which would definitely steer 
more purchasers to a certain platform, with the System/360 and PDP-11 
being two notable examples of major platforms for which a multitude of 
software was available from 3rd parties, which would have no doubt 
bolstered their dominance.


Even today, a modern rack of servers will be specced for the tasks it 
will run. Whilst the differences are by no means what they used to be, 
there's still no point putting a 96 core Threadripper in a machine 
running an Exchange server for a medium sized business. Some servers 
will be built specifically for the tasks they will run, and embedded 
applications being a prime example of commercial gear which has to cater 
for the software market. For the industrial and embedded market, for 
example, a lot of software still exists and is distributed that runs on 
MS-DOS and compatibles, requiring even modern boards to support BIOS 
level calls, as well as ISA and PCI slots for custom hardware. 
Industrial and embedded is a prime example of where the software needs 
dictate the hardware solution. For some companies that /still/ rely on 
PDP-11 gear, there are vendors out there that can interface your custom 
QBUS and UNIBUS hardware to interact with a virtualised PDP-11 running 
on an Intel PC box. "technical debt", as some call it, is rife in many 
industrial sectors, and will not be fully replaced with a "modern" 
solution for decades to come.


However, lets contrast it with the home market. For most, it's not the 
"computer you want", but the "computer you can afford". Back in the 
"early days" (and i'm calling the early days the mid 70's here), 
computers were still very new and novel for the home user. Those that 
might have been used to VAXen and PDP-11's at work may have lusted after 
one to tinker with at home, but their budget probably stretched to an 
Altair 8800 at best. Which is great if all you're doing is tinkering 
with it and writing some assembly yourself, as many hobbyists did. Of 
course, each platform gained it's own following and software became 
available, but for the home user, there was largely no "killer apps" 
that dictated the hardware purchase. Later on in the 80's, as home 
computers became more mature, some platforms became more powerful and 
dominant than others, but for those that couldn't afford a top end home 
computer, the cheaper end often sufficed. Most of the tasks that home 
users wanted to complete (gaming, word processing, maybe some 
spreadsheets) had software packages available for most home computing 
systems, with lower graphical performance or computing power usually 
correlating with what the user could afford at the time. Every system 
had it's own quirks, and users often had to sacrifice something.


Compare it to the world of modern home computing. Whether your own a 
Macbook or Windows PC, each has competent software packages for 
performing your tasks. In some ways, for most non-gaming tasks, the 
platform just does not matter any more. If you're a gamer, the size of 
your paycheck will be the biggest determining factor in your hardware 
purchases, and whether you can support running games in 4K at 144FPS or 
if you can access the full library of modern console titles.


So in some senses, nothing has changed. Business are always worried 
about costs, so will often buy exactly what they require, and nothing 

[cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so....

[Joshua Rice via cctalk]

On 15/04/2024 15:00, Bill Degnan via cctalk wrote:

I'll bet the source was talking about large contemporary storage units that
looked like drums or may have been called "drums" but were not actual 50's
drum memory with tubes and such.  There was no rotating drum storage, the
media rotates in the PDP era.

Take a look at any pdp 11 peripheral handbook, there would be drum memory
there if it was an official product.

Bill


There is a mention of drum memory storage in the PDP-11 Memory 
Management handbook: 
http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-11-HGKTCB-D%20PDP-1145%20Memory%20Management%20Reference%20Manual.pdf 
page 21


I imagine that any "drum like storage" attached to an 11/45 would be 
fixed head disk storage rather than actual drum memory. After all, from 
a digital perspective they're identical. Josh

[cctalk] Re: Intel 4004

[Joshua Rice via cctalk]

On 21/11/2023 09:03, ED SHARPE via cctalk wrote:

So what are the other contenders and what do they bring to table


The 4004 was definitely the first commercially available single-chip CPU 
on the market, but if you include multi-chip LSI designs, the lines get 
blurry.

[cctalk] Re: The World Wide Web

[Joshua Rice via cctalk]

LTO-9 is probably not the best route for "Sneakernet" transfers. When 
Tanenbaum uttered that famous quote, tape was still relatively fast (at 
least sequentially), as well as it having unparalleled capacity.
Nowadays, if you were to do large-but-fast data transfers, i'd chuck all 
the data on a large SAN and put that in the back of the van. Amazon AWS 
offer a similar product when moving data from one place to another.
Of course, if you had enough LTO-9 drives to load/unload data all in 
parallel, the transfer time would probably be in the same ballpark as 
the SAN. But keeping the data synced would be a nightmare, and all those 
LTO-9 drives would be horrendously expensive.
Yes, a van full of data hurtling down the highway will still have much 
more bandwidth than an internet connection, but nowadays what's in the 
back of the van is unlikely to be tape.

Cheers,
Josh Rice

-- Original Message --
From: "Stefan Skoglund via cctalk" 
To: da...@kdbarto.org; "General Discussion: On-Topic and Off-Topic 
Posts" 

Cc: "Stefan Skoglund" 
Sent: Monday, 2 Oct, 2023 At 10:08
Subject: [cctalk] Re: The World Wide Web
The main problem with that lorry hurtling down the freeway is
latency.
I need to move 1 PB . how long will it take filling and packing
enough IBM LTO-9 tapes to send 1 PB ?
How long does it takes to fill 1 tape with 18 TB ?

[cctalk] Re: For Fred, especially: "Everything I know about floppy disks"

[Joshua Rice via cctalk]

On 09/09/2023 00:02, Fred Cisin via cctalk wrote:


It's odd that he brings up things such as 100tpi drives (VS 96tpi)
and 3" (but not 3.25" on which Dysan bet the company), the very early 
40 track 3.5",

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


What confused me, is that i believe the 3.5" Sony Microfloppy originally 
had 70 tracks. I'm personally completely oblivious to any 40-track 3.5" 
microfloppy formats.


I have a pair of Sony OA-D30V drives, which i believe were the first 
commercially available 3.5" microfloppy drives, and they have a single 
head. The format the machine that they're linked up to only uses 70 
tracks (though the drives might be capable of a few more?) for a SSDD 
format of 315KB.


40 track 3.5" microfloppy drives therefore seem more of a branching 
derivative rather than the "predecessor" that the article seems to 
allude to. Unless, of course, we're talking of an unrelated format that 
just used the same size disks...


The early Sony Microfloppy is definitely not quite the standard "modern" 
3.5" floppy disk we're aware of today, but is still largely compatible 
with modern disks, with slight modification. Namely the drives have no 
mechanism of opening the shutters, so i've found the easiest method is 
taping the shutters on the disks open with a bit of sellotape.


Josh Rice

[cctalk] Re: Friden (was Silly question about S-100 and video monitors)

[Joshua Rice via cctalk]

On 01/09/2023 19:39, Paul Koning via cctalk wrote:

There's actually a pull in two opposite directions.  One is to put more stuff 
within a chip (System On Chip approach) and make the interconnects inside very 
wide, perhaps an entire L1 cache line wide.  The Raza/NetLogic/Broadcom XLR and 
its successors are a good example, very nice MIPS-64 SOCs.  The other is to do 
off-chip interconnects serially at very high clock rates.


Indeed. Internal interconnects are quite easy to keep a consistent 
propagation delay. In a similar fashion, (i believe, correct me if i'm 
wrong) most memory buses are also parallel. It's easy to keep the 
propagation delay consistent when it's essentially baked into the 
product. Things like expansion buses and "external" buses like USB can't 
guarantee that the propagation delay is consistent, and as such, can't 
operate at a significant speed.



Of course there are cases where serial isn't fast enough.  The fastest 
Ethernets are an example, with their multi-lane transceiver buses. Another is 
the JESD204 standard, used in signal processing to connect A/D and D/A 
converters, where you might be looking at multiple analog data streams, 14-16 
bits wide, multiple Gsamples/second.  That might takes 2-8 serial links working 
together.  For those, there isn't a requirement for alignment of the bits 
across the wires, instead the data streams are reconstructed serially for each 
lane and then aligned properly to form the words.  So within reason the lanes 
may have different propagation delay and still work.

paul


This is essentially how PCIe works. It's easier to take multiple high 
speed serial streams, and reconstruct the data afterwards, than it is to 
operate those lanes in a synchronous way. Logic is simpler, and 
bandwidths are higher.


Generally, the serial vs parallel problem has been solved by using 
multiple serial streams in parallel. True parallel buses are really only 
useful when latency is a bigger issue than throughput, as whilst serial 
buses can be fast, it still takes a significant amount of time to 
reconstruct the data into words, even if you can do a lot very quickly. 
For most uses, that kind of low latency performance just isn't needed.


Josh

[cctalk] Re: Apple 1

[Joshua Rice via cctalk]

Value is a very much reliant on both desirability and historical significance. 
I guarantee most people who own an Apple 1 never use it, and it sits in a 
cabinet/shelf somewhere. Transversely, I’m sure there’s very few Amiga 1200’s 
purely on display, with the vast majority in collectors hands either tucked in 
a cupboard or actively used. 

The Apple 1 is collectible purely because it was the first product Apple made. 
There’s dozens of similar machines from the same time period, vcreated by 
startups looking to be the next big thing, that just didn’t make it. Look at 
SWTPC, look at IMSAI, the COSMAC ELF. Apple made it to the big time, and they 
didn’t, so many more people with too much money would consider the Apple 1 to 
be a wise investment. 

I’d still prefer the IMSAI 8080 or SWTPC 6800 though.

Josh

Sent from Mail for Windows

From: Christian Corti via cctalk
Sent: 03 August 2023 07:07
To: Murray McCullough via cctalk
Cc: Christian Corti
Subject: [cctalk] Re: Apple 1

On Wed, 2 Aug 2023, Murray McCullough wrote:
> Classic computers have a value in our capitalist society. Take the Apple-1:

Not necessarily. Something only gets a value if there is a demand or 
market. As I repeatedly see old classic systems scrapped because nobody 
wants them/has space to store them, there can't be such a high value. For 
example, how do you tax a Mincal 523? We have the only one that survived. 
I'd say, it's "priceless", you can't attribute a value to it, because 
there's neither a market nor a reference to compare with.
The only reason why the Apple 1 has a monetary value is because it has 
become a pure investment object. Everything else is just worthless, except 
perhaps the video shift registers ;-)

Christian

[cctalk] Re: Getting floppy images to/from real floppy disks.

[Joshua Rice via cctalk]

-- Original Message --
From: "Tony Duell via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Cc: phi...@axeside.co.uk; "Tony Duell" 
Sent: Sunday, 28 May, 2023 At 07:17
Subject: [cctalk] Re: Getting floppy images to/from real floppy disks.

I suspect USB-SCSI interfaces exist but I've not looked into one.
Since SCSI is a 'formatted' interface it shouldn't be too hard to make
pseudo disk drive using flash memory. I must look into that to make a
SASI drive for my P2000C.



I'm suprised to hear you're familliar with the GreaseWeasel but have 
never heard of BlueSCSI. ( https://scsi.blue/ ). Though SASI 
compatability seems "possible but not guaranteed", being an open source 
project, you can probably wangle the existing PCB's/software to be SASI 
compliant. More research, that i can leave you to perform, will probably 
help with that endeavor.


As for a means to interface SCSI to USB, they do exist, but are often 
expensive and of debatable compatibility. You will almost always have a 
much better experience with a SCSI PCI card in an (and i don't mean to 
push the subject) older PC.


Still works, or at least it did when I last powered it up. But no easy
way to read USB sticks or SD cards on it.
-tony


The XT-IDE ISA card is probably what you'll want. Though it doesn't 
"natively" support SD cards, there are IDE/CF adaptors to SD cards that 
can provide a means and ways of interfacing an older PC with modern 
media. ( https://users.glitchwrks.com/~glitch/xt-ide.html )


Anyway, you seem to truly have your heart set on the Greaseweasel. As 
long as you can write, or find, software that can turn the Weasels 
output into something useful, i'm sure it will suit your purposes fine. 
Of course, if you're archiving software froma truly unknown format, it 
will almost definitely be the best solutions. Getting useful data into 
and out of it is where the trouble will be.


Good luck!


Josh

[cctalk] Re: Super I/O chips and Getting floppy images to/from real disks

[Joshua Rice via cctalk]

What op sys and version do you want to run on it? Windows changed the 
way drivers work after Xp so it may be an isshe. That made replacement 
of older PCs that controlled equipment like xray, MRI, and industrial 
stuff impossible as the manufacturers couldn’t write new drivers — lost 
the knowledge thru mergers and retirements/buyouts.



As i say, i'm in the market for a laptop. Omniflop, the tool i used to 
write the RCA MicroDOS floppies, works well with Win2k, and i used a 
Dell GX1 running Win2K to write the disks. The direct 
drive-to-controller-to-OS links are what i'm after. No USB, Firewire, or 
serial/parallel interfaces between the controller and rest of the 
machine.Ideally, i'm after an early 2000's laptop. I've got a couple 
mid-2000's Dell laptops with floppy modules, but they interface over 
USB, which is a no-go for device-level stuff. I figure something from 
before, or the early days of USB 2.0 is where i need to look, but i've 
seen some machines that use/repurpose the parallel ports for floppy 
interfacing. If the SuperIO chip sends direct drive controls across the 
parallel port, as i've read somewhere, then i see no issue. But if the 
floppy controller is on the drive side of the parallel port, and the OS 
requires dedicated drivers to controll it, i imagine i won't have the 
drive-level control i require.

[cctalk] Super I/O chips and Getting floppy images to/from real disks

[Joshua Rice via cctalk]

Interestingly, i'm looking at procuring a reasonably vintage laptop for 
a computer festival i'm planning to attend soon. It seems that many 
laptops of the PIII era use SuperIO chips, but i'm rather confused as to 
how "low level" they get.




Some of you may remember my RCA MS2000. I've had great luck writing 
bootable images from a PIII machine with a "standard" 1.44mb floppy 
drive, despite the format being 70-track, SSDD. The machine's floppy 
controller uses a bona-fide NEC uPD765 though, so no surprises it worked 
fine... ( Here's a video of me playing around with it for the curious... 
https://www.youtube.com/watch?v=qdKkaf-77dE )




I'm really asking if anyone has any recommendations for a laptop that is 
reasonably powerful, fairly modern (has USB), but also has a 
direct-connection floppy drive that can do device level shenanigans (via 
Omniflop) to allow me to write floppies in obscure formats. Bonus points 
if it can use it with a serial terminal emulator, and run the Emma02 RCA 
1802 emulator on it as well. I, like Tony, don't drive, so i need 
something compact and portable for public transport travel.




I've been eyeing up a Dell Latitude C series (C600?) But the whole 
SuperIO-over-parallel thing makes me think there might be proprietary 
drivers involved, preventing device level access of the floppy drives... 
Hopefully some of you might be a bit more wise.




Cheers, Josh

[cctalk] Re: Getting floppy images to/from real floppy disks.

[Joshua Rice via cctalk]

> 
> My advice: buy an old desktop computer.  Buy a standard PC floppy drive (a 
> dual drive if possible to give both 3.5 and 5.25 support).  Then run Linux, 
> use the "fdparm" tool to set the media format if necessary, and copy the 
> image with "dd".
> 
> Roughly speaking this is how I read and write RX50 floppies.  More precisely, 
> I usually do it with my "rstsflx" tool, which (a) understands RSTS file 
> systems so I can manipulate things at that level, and (b) knows about RX50 
> interleaving and how to issue the ioctl that sets 10 sector per track format.
> 
>   paul
> 

My views exactly. 

I’ve had great experiences with a PIII Dell GX1. I’m most comfortable in a 
Windows enviroment, and have found both PUTR, for DOS, and Omniflop for Windows 
NT, to be perfectly suitable for writing disk images. PUTR is mainly for DEC 

As for loading in/loading out files from images, there’s likely at least 
something out there you can make use of. Even if there’s no host OS native 
software for writing directly to images, there’s almost certainly an emulator, 
which would work off disk images that can later be written to real hardware 
disks.

Ultimately, there are ways and means to do this, but ultimately an older PC 
with a real floppy controller is by large the easiest way.

Josh

[cctalk] Re: Using Teledisk 2.16 to read old RX50 images

[Joshua Rice via cctalk]

I’ll chip in my 5 cents and say that i’ve had good experiences with PUTR, a DOS 
based utility can can read, write, and mount a lot of DEC formats. I quite 
successfully used it to make myself a few bootable RX50 floppies for my 11/23.

Of course, YMMV, and you’ll need a DOS/9x machine to use it, but from my 
experiences, it’s really quite powerful, and though i haven’t used it for disk 
imaging, i’m pretty sure it supports that too.

Josh.

> On May 14, 2023, at 5:12 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 5/14/23 06:58, Warner Losh via cctalk wrote:
>> On Sun, May 14, 2023, 7:47 AM Chris Zach via cctalk 
>> wrote:
>> 
>>> Hi!
>>> 
>>> Well, after a good bit of work I have finally gotten my Compaq XE4000 up
>>> and running with Windows 98, the BIOS all set, a new battery, and of
>>> course a 1.2mb 5.25 floppy that seems to be working.
>>> 
>> 
>> I'd avoid teledisk.  I'd look at Dave Dunfield's ImageDisk. It produces
>> those img files directly.  It's linked from
>> http://dunfield.classiccmp.org/img/index.htm
> 
> ImageDisk may not be the answer either.
> 
> A problem that crops up if you're trying to run TeleDisk under a Windows
> command prompt.  That messes with the timing.  TD is intended for use
> under real-mode DOS.  That is, if you're in windows, shut down to a DOS
> command prompt.  Do NOT assume that the Windows command prompt out of
> the GUI will do the job.  Or just boot MS-DOS.
> 
> There are certainly Linux programs that can also read RX50 floppies.
> 
> If you want a brute-force read every sector on an RX50 program, I can
> pass that on to see if it works better for you.  It knows the format of
> an RX50 disk, so doesn't have to guess.  I use it myself (the author of
> TeleDisk), though increasingly, I'm relying on MCU-based solutions to
> handle floppies.
> 
> I haven't touched TD since 1999, when we sold the rights to the program.
> It blows my mind that it's in use 24 years after its last incarnation.
> 
> --Chuck
> 
> 

[cctalk] Re: what is on topic?

[Joshua Rice via cctalk]

The subject to f that is and what isn’t vintage computing is an argument as 
ancient as the computer itself. Fact is, it’s a moving target. As every year 
passes, products you can categorise as “vintage” changes at different rates. 
For example: IBM PC’s have largely standardised and “stagnated” in the last 
10-50 years. A machine from 2010 is largely similar in operation as a machine 
from 2022. However, an iPhone from 2010 (such as the iPhone 4), is woefully 
obsolete compared to modern offerings. Certain product lines and categories age 
worse than others. Another example is the PPC Macintosh line. Radically 
different, and largely unsuported, this range of computers were only 
discontinued in 2006, but i’m sure there’s no argument that they’re pretty 
on-topic. 

What is defined as on-topic and off-topic is something we can argue until the 
cows come home, but utimately it’s a matter of opinion. However, i believe that 
this list, in particular, seems to aim at the weird and wonderful, regardless 
of decades. There’s people on this list who are experts at the Apollo Guidance 
Computer, there are people here who understand the BeBox. There’s people here 
who have experience with Cray supercomputers and Connections Machines 
supercomputers. 

There’s places to discusss early 00’s winboxes, 8-bit home computers, or video 
games consoles. But ultimately, if i’m interested in information on some 
obscure 70’s-80’s-90’s-00’s box of chips, i bet this list is the place i can 
get an answer.

I think, in general, this list is ultimately aimed at the “weird and wacky”, 
and not any sort of age. Even if that is pretty frab run-of-the-mill stuff like 
modern winboxes or 8-bit consoles. Looking to see how to rig an acoustic modem 
and a 5.25” drives to a Server 2003 machine? Here’s a good place. Looking for 
ROMs for your C64? Probably not.

Cheers, 

Josh Rice

[cctalk] Re: Soviet PDP clones

[Joshua Rice via cctalk]

-- Original Message --
From: "Holm Tiffe via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Cc: "Holm Tiffe" 
Sent: Tuesday, 18 Oct, 2022 At 08:45
Subject: [cctalk] Re: Soviet PDP clones
Joshua Rice via cctalk wrote:
Hi all,
After some discussion on reddit about russian PDP-11 clones, i made the 
(perhaps erronous) claim that the PDP series in general was cloned by 
the Soviets.
I’m aware that there was a lot of QBUS/LSI PDP-11 clones, and depite 
poor documentation, there is significant evidence of PDP-8 clones. Also, 
depite not strictly a “PDP”, the VAX series was also cloned.
However, i’m curious whether anyone has any evidence of either the 
18-bit or 36-bit PDP machines being cloned? I imagine that given the 
rather lacklustre success of the 18-bit series, that there would have 
been less demand for an 18-bit PDP machine in the Soviet Union, but i 
find it quite hard to believe that no attempt to clone the PDP-6 and 
PDP-10 machines would have been attempted.

Does anyone here have any information on such clones?
Cheers,
Josh Rice
Josh, it seems to be difficult for any "western" guy to belive that
russians or the "warshaw pakt countries" where able to develop ther own
systems of computers, that's simply wrong.


Hi,

I apologise for any misunderstanding. By "clone", i didn't exactly mean 
a 1-to-1 copy, but more a reimplementation. Much like the term "IBM PC 
clone" is still used to describe non-IBM-derived PC designs.


I understand that the eastern european countries can and di design their 
own machines, but it's undeniable that the Soviet leaders deemed it more 
valuable to copy western designs than design their own domestic 
architectures from scratch. There was also plenty of designs that were 
literal "clones", down to the silicon gates.


Cheers, Josh

[cctalk] Soviet PDP clones

[Joshua Rice via cctalk]

Hi all, 

After some discussion on reddit about russian PDP-11 clones, i made the 
(perhaps erronous) claim that the PDP series in general was cloned by the 
Soviets. 

I’m aware that there was a lot of QBUS/LSI PDP-11 clones, and depite poor 
documentation, there is significant evidence of PDP-8 clones. Also, depite not 
strictly a “PDP”, the VAX series was also cloned.

However, i’m curious whether anyone has any evidence of either the 18-bit or 
36-bit PDP machines being cloned? I imagine that given the rather lacklustre 
success of the 18-bit series, that there would have been less demand for an 
18-bit PDP machine in the Soviet Union, but i find it quite hard to believe 
that no attempt to clone the PDP-6 and PDP-10 machines would have been 
attempted. 

Does anyone here have any information on such clones?

Cheers, 

Josh Rice

[cctalk] Re: Xerox 820II U07 Power Supply magic smoke....

[Joshua Rice via cctalk]

You shouldn't need a schematic. These thin film caps are a common 
failure mode on a multitude of PSUs. Just replace like for like. Thin 
film X and X2 rated caps are easily found from your favorite electronics 
part retailer.


If it's gold and got RIFA on it, replace it, though. Just because it 
hasn't popped, doesn't mean it wont pop in the near future.


I've learned now, to always check every PSU or other mains-powered 
vintage equipment for these little stinkbombs. If they're present, i'll 
always replace.


Cheers, Josh

-- Original Message --
From: "D. Resor via cctalk" 
To: "Classic Computer Mailing List" 
Cc: "D. Resor" 
Sent: Thursday, 13 Oct, 2022 At 12:24
Subject: [cctalk] Xerox 820II U07 Power Supply magic smoke
Where might I find a schematic diagram for the Xerox U07 8" FDD,HDD
expansion cabinet for the 820II, and/or the 105P80450 power supply?
The Xerox Professional Computer Technical Reference Manual I downloaded 
from

bitsavers.org doesn't seem to have those particular schematic diagrams.
For your enjoyment the part which smoked.
https://www.dropbox.com/s/al9kx3yw9ypwp89/Xerox105p80450.jpg?dl=0 

I certainly am glad I have the lid off while testing.  Unfortunately 
these

capacitors which appear to be film type were hidden from view.
The fuse didn't blow, but that .22uf 250v capacitor certainly stunk up 
the
house.  It smelled like burnt popcorn, plastic and the bottom of a 
coffee

pot which has boiled dry, yech!
I know that if I had pulled the power supply board first I might have 
seen

the physical cracks in these boxed capacitors.
Wasn't it Marc V. that said in one of his videos, you don't need to 
shotgun

them all! Oi, lol
It's when things like this happen that I most always worry about not 
going

over vintage equipment fine tooth comb.
Don Resor

[cctalk] Re: Minicomputer front panel.

[Joshua Rice via cctalk]

-- Original Message --
From: "Adrian Stoness via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Cc: "Adrian Stoness" 
Sent: Sunday, 25 Sep, 2022 At 14:42
Subject: [cctalk] Re: Minicomputer front panel.
yea was found in the mud the press board preic spent a few yrs outside
after i found the first bits yet it survived had put it under some 
weight

for few weeks to get rid of the curve it had
https://live.staticflickr.com/4159/34433937071_ddcbdb994a_b.jpg 





Wow, that thing is pretty well wrecked.

I have a bunch of PDP-8 flips chips i bought for display purposes, but i 
wouldn't mind them to go to a restoration. I'll have a look and see what 
i've got.


There is (was?) a very good resource listing most flip chips, with good 
photos of each and even sometimes PCB layout files somewhere on the 
internet. https://www.pdp8online.com/r-boards/r-boards.shtml#pictures 
seems to have some, but isn't quite what i remember finding.


All the best in that very challenging restoration.

Josh

[cctalk] Re: Minicomputer front panel.

[Joshua Rice via cctalk]

> On Sep 23, 2022, at 5:45 PM, Chuck Guzis via cctalk  
> wrote:
> 
> I thought it curious that many 1960s-1970s supercomputers lacked front
> panels and blinking lights altogether.(e.g. Cray I, CDC
> Cyber/600/700, etc.)  Indeed, the Cray couldn't even spin a tape without
> help from another system doing the I/O.
> 
> --Chuck
> 

The Cray was often coupled witha DG nova for bootstrapping, which very much did 
have a front panel on it. Indeed, many models of PDP-10 were bootstrapped by 
PDP-11’s with front panels, even if the PDP-10 lacked one. The CDC Cyber 
however, had “dead start” panels hidden behind shouding, which could be used in 
a very similar way to a front panel.

By the mid 70’s and early 80’s, ROM chips had largely replaced front panels, 
initialising the system and performing boot routines that were otherwise done 
by front panel. You can see this approach in later PDP-11/s and even PDP-8’s

Josh

[cctalk] Re: Minicomputer front panel.

[Joshua Rice via cctalk]

It is sacrelege! 

In all honesty, real front panels are expensive. An 11/40 front panel sold 
recently on eBay for $2000! (https://www.ebay.co.uk/itm/314122754771 
) 

They’re also hard to come by, and most that have them are going to be very 
reluctant to part with them.

I suggest, if you want a display piece, the very good replicas done by Oscar 
Vermeulen. He offers both a PDP-11 and PDP-8 replica kit, powered by a Rasberry 
Pi and the SimH emulator. He is also working on a PDP-10 replica as well.

These are reasonably priced, and very good quality, working, scaled replicas of 
their respective systems. 
(https://obsolescence.wixsite.com/obsolescence/pidp-11 
)

It’s worth noting that other replica front panel systems are available as well, 
including, but not limited to the Altairduino 8080

> On Sep 22, 2022, at 6:05 PM, Peter Van Peborgh via cctalk 
>  wrote:
> 
> I know this is sacrilege but I am looking for the front panel of a *Data
> General Nova *and/or *a DEC PDP 8/11/12/15*.
> Why? I collect artefacts from the days of the minicomputer and earlier and
> I want them for my collection/display. They should be not too damaged and
> of course do not need to be functional. I would be willing to pay
> postage/freight.
> Any offers? Any offers?
> Peter
> 
> PS Please don't shout at me!

[cctalk] Re: Flipping an 8" diskette

[Joshua Rice via cctalk]

-- Original Message --
From: "Fred Cisin via cctalk" 
To: "Chuck Guzis via cctalk" 
Cc: "Fred Cisin" 
Sent: Friday, 2 Sep, 2022 At 01:45
Subject: [cctalk] Re: Flipping an 8" diskette

Didn't HP continue to say "disc"?
MOST switched to "disk".
HOWEVER, the strong influence of Philips on compact disc meant that CD 
and DVD became "disc".

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


This is no way a standardised thing. But generally i call a "disc" in a 
case (of some sort) a "disk", IE hard drives, floppy disks, CD's in 
caddies. And a bare media as a "disc"


Josh

[cctalk] Re: Dec rl02 disk pack shelf design

[Joshua Rice via cctalk]

I have definitely seen pictures of them stacked edge-on. Since they were 
essentially identical physically to the IBM 5440 disk packs (though 
formatting would be wildly different), i imagine that might be a good 
place to start in regards to existing designs. Alternatively, it should 
be trivial to knock one together with some ply and dowels.


https://collection.motat.nz/records/images/xlarge/35979/3a9db5d799ac1fe3783402cbe0e8a525fcd10503.jpg


Cheers, Josh

-- Original Message --
From: "devin davison via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Cc: "devin davison" 
Sent: Monday, 8 Aug, 2022 At 21:21
Subject: [cctalk] Dec rl02 disk pack shelf design
Hello,
I have many rl02 disk packs for my pdp 11/34 and 11/05. I have just been
stacking them upright, but that has not been the safest or the most 
space

efficient. Were any kinds of shelves made for these disk packs, perhaps
similar to 9 track hanging tape racks? Trying to make things look more
organized too.
Hoping someone here has one and can share a pic, perhaps it is a design 
i

can duplicate and make with some woodworking tools.
Thanks,
Devin D.

[cctalk] Re: VT220 North of Boston

[Joshua Rice via cctalk]

You say that, but Galway is just a county over, and DEC had a large 
manufacturing base there. It's entirely possible for there to be a VT220 
rotting in someones loft or barn in the vicinity of Boston, Ireland.




I believe this is on the same isle, and the same state
https://en.wikipedia.org/wiki/Boston,_County_Clare 

I checked on Google Maps and there is a big sign saying welcome to 
Boston

and little else, so I suspect a total lack of VT220's
Dave
G4UGM

Re: Free stuff in Somerset, England

[Joshua Rice via cctalk]

Times like this make me wish i could drive... I'm not even that far 
away, just down from Bournemouth.
I'd be very interested in the 11/10 and the VT100 though, if only i 
could figure out a way to collect them.
Good luck to all anyway. And if anyone is going past Bournemouth on the 
way here, give me a shout :)


-- Original Message --
From: "Philip Belben via cctalk" 
To: cct...@classiccmp.org; declut...@axeside.co.uk
Sent: Monday, 27 Jun, 2022 At 19:06
Subject: Free stuff in Somerset, England
Dear all,
The cost of living crisis means that I can no longer afford to rent the 
space to store all my collection.  I have therefore decided to give some 
stuff away to anyone who will come and collect it.
Some stuff is in a storage container in Wells; the rest is in my 
basement between Shepton Mallet and Radstock.  (I will give you the 
actual address and instructions to find the place when we've agreed an 
appointment for you to visit.)  As noted above, these addresses are in 
Somerset, England.
The following stuff is definitely available.  Visitors will also be 
welcome to look around my basement and ask for stuff.  I don't guarantee 
to let it go, but I want to (a) empty the storage container and (b) make 
enough space in the basement that I can get at anything I want to work 
on, and work on it.

DEC PDP11 stuff:
A complete 11/10 system - processor box (in a 3U rack mount box - this 
is, I am told, unusual, but it is original), one expansion box, RKO5. 
All mounted in a later (1980s era) half height rack.  (I gave the 
original full-height rack to Toby)
An 11/34 processor box.  Don't know whether I have all the innards.  (No 
idea where it came from!)
The remains of my 11/44 system.  I bought the complete system - 
processor, expansion box, two RL02 drives, RX02 drive, RA80.  I started 
buying stuff to add to it - tape drive, a couple of CDC multi-platter 
hard drives.  I then sold a basic system - processor, one RL02 drive, 
RX02 drive, all in one rack - but have all the rest (except the RA80, 
which I gave to Tony Duell).  So there's a lot of stuff, but probably 
not all the boards (no RL11, for example).  But if anyone wants to build 
an 11/34 system from the bits, they're welcome to try!
A number of DEC hex-height boards and other Unibus stuff.  Probably some 
spare boards for the 11/10.  And a couple of racks from the 11/44 
system.

Other stuff:
A DEC VT100 with no keyboard
a motherboard from an Alphastation (Rod Smallwood has first call on this 
- it was supposed to be in one of the alphastations I gave him years 
ago.)

A Teletype 43
A Perq 2T2 in bits.  It has no working monitor, but I think I can find 
all the other bots.
A Silicon Graphics Personal Iris, also with no monitor, but I have found 
its keyboard and mouse, and some additional boards that may belong to 
it.
an IBM "portable" PC, i.e. an XT with built-in monitor in a luggable 
case.

Lots of DEC manuals - I've not sorted this box.
A Calcomp 1039 plotter.
Five HP Series 80 machines (85, 86, 87) and a box of manuals and 
accessories.  (You are not allowed to take any accessories unless you 
take at least one system unit!)
The other stuff in my basement was mostly acquired from car boot sales 
and clearouts at work in the 1990s and early 2000s, so there's a lot of 
1980s micros there.  I have several Commodore PETs of various flavours; 
I'm probably going to keep my first ever 2001, and an 8296, but most of 
the stuff in between can go.
Please let me know if you are interested, and I can post photos and/or 
more detailed descriptions.  If I don't get any interest, the CDC drives 
and probably the Calcomp plotter, will have to go to the tip.
Everything is offered as seen.  Most of it doesn't work.  You have been 
warned.
Finally, I have set up an e-mail address for you to reply to if you are 
interested: declut...@axeside.co.uk.  I hope to spot replies to the list 
too, but it will help if you copy them to that address as well.

Many thanks,
Philip.

Re: RCA COSMAC MS2000 MicroDisk Development System

[Joshua Rice via cctalk]

On with the saga of the COSMAC MS2000…

I powered it up a few days ago. The ROM boots, nothing smoked, the drives whirr.

However, one of the RAM boards (the lower 32k) seems to have failed with a 
stuck bit. it outputs the rather humourous message of BAD RAM P00 (where P00 is 
memory page 00h). poking at various memory locations seem to reveal that they 
are populated with 40h instead of 00h. I tried reseating th card, and swapping 
backplane slots, to no avail.

Now my first assumption was that the tc40h245p bus buffer might have an open 
short driving one of the lines high, but probing it with a multimeter hasn’t 
revealed anything enlightening, with all resistance values being practically 
identical. Sadly, this seems to be the only thing between the RAM chip’s data 
bus and the card edge connector. Continuity seems fine on all pins.

Is it entirely possible that one of the RAM chips has an open short and is 
pulling the line high? How would i go about testing this without desoldering 
every chip off the board? I fear my soldering skills (and tools) aren’t up to 
the skill level required for such an endeavor, and i’m really paranoid about 
killing something that’s practically irreplaceable. One chip is probably fine, 
but a whole board is just asking for trouble.

I hope someone here can shine some light on the matter. I’m really flying from 
the seat of my pants on this one, and thoroughly understand i’m way out of my 
depth! It’s entirely possible there’s something i’ve overlooked.

For reference, this is the offending board: https://i.imgur.com/G2zMw7t.jpeg 
https://i.imgur.com/rrHvl4C.jpeg

The data lines on the card edge connecter start from the 3rd finger from the 
top, and carry on down 8 fingers. It’s a dual sided board, no layers here. 

Thanks, 

Josh Rice

Re: Felt pads for RX50

[Joshua Rice via cctalk]

Never had to replace them, but from what i remember, from cleaning out 
an RX50 last year... they're thinner than cassette tape felt pads.



I imagine sticky back craft felt would be an adequate replacement. 
Cutting it/stamping it out might be the tricky part.



https://www.bakerross.co.uk/self-adhesive-felt-sheets-classpack - Craft 
felt


https://www.amazon.co.uk/Cutters-Stainless-Indentation-Ceramics-Dotting/dp/B07VDNY82V/ref=asc_df_B07VDNY82V/ 
- Clay cutters, might work, might not. Might be better off with a 
stanley knife and some steady hands


I'm really only hypothesising here... But if i was in your shoes, that's 
what i'd try.



Cheers,


Josh Rice


-- Original Message --
From: "Chris Zach via cctech" 
To: "CCTalk mailing list" 
Sent: Tuesday, 19 Apr, 2022 At 01:49
Subject: Felt pads for RX50
Anyone know of a source for the felt pads that go on the non-head side 
of an RX50? Missing at least one here.

C

Re: RCA COSMAC MS2000 MicroDisk Development System

[Joshua Rice via cctalk]

I’ve torn it down this morning and put some pictures on Imgur.

https://imgur.com/gallery/xwSvG8A 

Should be fairly comprehensive. It looks in good condition, with nothing 
obviously wrong with it.

If there’s anything i’ve missed, or that you’d like better pictures of, let me 
know. I suppose all that’s left to do is warm it up and see if it works. 

Cheers, 

Josh Rice

Re: RCA COSMAC MS2000 MicroDisk Development System

[Joshua Rice via cctalk]

-- Original Message --
From: "geneb" https://i.imgur.com/Q96sRhE.jpg 
Nice find!

g.


No, it looks like this: https://imgur.com/gallery/bHYFoBV


-- Original Message --
From: "David Schultz" 
You didn't mention my web page: 
http://davesrocketworks.com/electronics/1802/microdos/index.html 
 
which might have some additional information useful to you.



Thank you, i'm sure that will come in handy! Seems to be a rather poorly 
documented (and rather rare) system, so any information is good 
information!



Cheers



Josh Rice

Re: RCA COSMAC MS2000 MicroDisk Development System

[Joshua Rice via cctalk]

From: "Bill Degnan via cctech" ...but I bet yours 
is more like 1976-77. What is the CPU type 1802 or something else?


It's definitely an 1802 family CPU, not sure of exact model, but i'll 
find that out later when i tear it down (and document/post it here). 
However, it's much newer than '77. The "MicroDisk" part of the name 
refers to the two early Sony 3.5" drives mounted in the front of the 
machine, so it dates from about 1984. It uses RCA Microboard cards, so 
fundamentally it's very similar.


Here's a picture i took of it shortly after unboxing: 
https://imgur.com/gallery/bHYFoBV 


Cheers,

Josh Rice

RCA COSMAC MS2000 MicroDisk Development System

[Joshua Rice via cctalk]

Hi all,  

I’ve recently come across something i’ve soon realised really quite unusual. An 
RCA MS2000 MicroDisk Development System. 

I’m very green to the COSMAC scene, with this being my first 1802 machine. I’m 
very interested in knowing the pitfalls i may come across in restoring such a 
machine. I’ve had a quick cursory look over the machine, and it seems to be 
complete, with 2 RAM/ROM cards, CPU card, FDC and a (3rd party?) ROM programmer 
board, along with the PSU and floppy disk drives.

It’s my understanding that these are pretty similar to the RCA Microboard 
development systems, which i believe are also pretty similar to the ELF 
“homebrew” microcomputer this group revolves around. I’ve found some manuals on 
bitsavers,, a website on the Microboard system, along with disk images on the 
Emma02 emulator website, so I have a reasonable undertanding over what this 
actually is.

I have a week off work next week, so am planning on taking my time on 
disassembling and checking the unit over next week.

I’ll endevour to upload some pictures of said machine when i tear it apart.

Thanks, 

Josh Rice

Re: Glass memory?

[Joshua Rice via cctalk]

From: "steven--- via cctech" 
Paul and others said
What if you can't make ICs any more? Or rather, what level of IC
fabrication would it be possible to construct from scratch?
For semiconductors, you'd start with machinery to make ultra-pure 
materials (silicon, I'd assume).  A Czochralski crystal growing machine 
to make
the cylinders of pure mono-crystal silicon from which wafers are sliced. 
Polishing machinery.  Wafer coating machines.  Wafer steppers.  Etching,
metal coating, diffusion, etc. most of which also require very 
pure and often exotic ingredients.  (I remember being amazed to read 
that
chlorine trifluoride is used as a cleaner in the semiconductor industry. 
Look up the properties of that compound, it will blow your mind.)

Which brings to mind the amazing work of Sam Zeloof:
https://www.youtube.com/results?search_query=zeloof+z1+chip 




It really depends on how "from scratch" we have to go. In a more real 
world scenario where the ability to make large, low density MSI chips in 
the micrometer scale is somehow lost through scrapping and ignorance, 
recreating the machines required to make them on an industrial scale 
shouldn't cost a huge amount. It's proof, that if someone can make these 
chips in his garage on a shoestring budget, a few hundred grand should 
be able to recreate the technology in order to reproduce them 
industrially. Obviously there'd be an iterative process, much like 
happened in history, to shrink the die process if you were indeed trying 
to get smaller.


However, if we had some sort of massive scale Carrington event (or 
larger) that fried every IC ever made, things would definitely take a 
step back. I imagine that the large crystal-growing tanks themselves 
would be fine, but the control gear etc would be truly sent back to the 
dark ages. It might take 5 years or more to re-engineer all the control 
gear to work in an electricity-free (or at least IC free) world, with 
many other things like food, water and fuel supplies taking precedence. 
Then there's the task of re-engineering the IC production from paper 
copies of research papers and documentation (no internet, remember), 
which could prove rather difficult to duplicate and distribute without 
photocopiers. We'd essentially be taken back to the early 60's when it 
came to IC production, having to re-engineer everything from scratch. 
Much of the non-electronic machinery and R would still be available, 
so i imagine getting back to where we are now would only take 20 or 30 
years, instead of 60, but it would still be a long and iterative process 
which would be likely hampered by the whole "end-of-the-world 
Armageddon" thing the Carrington-scale event would have caused. I 
imagine most people would be worried about putting food in their bellies 
and keeping warm, rather than worrying about getting their Exchange 
server working.


I think i may have overthought this.

Josh Rice

Re: Core memory

[Joshua Rice via cctalk]

> On Apr 1, 2022, at 7:51 PM, Paul Koning via cctalk  
> wrote:
> 
> Neat looking stuff.  It doesn't look like core rope memory in the sense of 
> the AGC ROM, nor in the sense of the Electrologica X1.  It looks more like 
> the transformer memory used in Wang calculators that you documented in your 
> core ROM paper.
> 
>   paul
> 

I second the Transformer ROM theory. I guess the transformers are the epoxied 
modules on the top half of the board, with some weird magnetic/inductance 
wizardry at the bottom doing the adressing. You may find it’s a hybrid of core 
rope and transformer ROM for super dense ROMs. I’m no expert at the nuances of 
this field though.

Reminds me a bit of my Wagenr Computer transformer ROM: 
https://www.reddit.com/r/vintagecomputing/comments/m3pe29/a_very_photogenic_rom_board_from_an_early_70s/
 

 

Cheers, 

Josh Rice 

Re: PDP 11/24 - A Step Backwards

[Joshua Rice via cctalk]

-- Original Message --
From: "Chris Zach via cctalk" 
To: r...@jarratt.me.uk; "'General Discussion: On-Topic and Off-Topic 
Posts'" 

Sent: Tuesday, 29 Mar, 2022 At 00:11
Subject: Re: PDP 11/24 - A Step Backwards
I have been reluctant to put everything back in, in case the PSU fries 
something. And the ripple I noticed is...
For the record, right now I have only the M7133, M7134 and G7273 
installed.
Ok, I do recall that my 11/24 wasn't doing any ODT without some form of 
memory. When I configured a (broken-ish) MS11-PL in it did at least come 
up and allow me to load memory addresses and the like.
But no memory, no deal. I'd say figure out your PSU first, then memory, 
then stuff.

C


Just to chip in my 5 pennies worth. At least in the QBUS world, the only 
chipset that wouldn't ODT without memory is the original LSI-11 (and the 
T11 i believe, but that's moot because they came with RAM onboard). You 
should still get ODT on F11 and J11 chipsets even without RAM.


Since the 11/24 uses the same chipset as the 11/23, i assume that this 
would still apply. Not sure of the intricacies of UNIBUS, having had no 
experience, but i assume that if the bus was terminated or continuity 
cards inserted correctly, the CPU board should ODT without memory. It's 
likely that the lack of ODT is due to issues with other boards, the 
backplane (an often missed source of issues), or the bus 
termination/continuity.


I'd start with the basic stuff first. Whilst you're waiting on your PSU 
to be serviced in warranty, check the backplane and cabling for foreign 
objects, damage, and corrosion. Shorts and intermittent connections are 
inherently difficult to troubleshoot assembled, but can be trivial to 
identify when the machine is torn down. Then i'd reinstall the PSU and 
fans etc, then work on bringing up the machine, starting with the CPU 
and memory, then other devices.


One notable thing, is i believe most PDP-11 PSUs, regardless of bus 
type, won't function correctly without a load on them. It might be hard 
to troubleshoot without a load on it.


If you're short of grant continuity cards, they're extremely simple, and 
i'm sure with some googling, gerber files can be found for them. It 
should be trivial to make some from copper plated PCB stock and some 
patience if time is pressing.


Good luck in your endeavors!

Josh Rice

Re: LSSM is chasing this, was Re: General Data? Computer Equipment Auction - GSA

[Joshua Rice via cctalk]

-- Original Message --
From: "Dave McGuire via cctalk" 
To: "P Gebhardt" ; "cctalk" 


Sent: Thursday, 17 Mar, 2022 At 21:37
Subject: Re: LSSM is chasing this, was Re: General Data? Computer 
Equipment Auction - GSA  As I've said privately today to three people 
who have emailed me off-list about this, since starting the LSSM project 
about ten years ago, I've seen many, probably 25, situations in which 
widows have junked their dead spouse's prized computer hardware.  We've 
all heard of those situations, but as we've been actively looking for 
hardware, we see it a lot more, and even I was shocked about just how 
common this actually is.  This is a fate that seems to befall most 
private collections.
  That, combined with rodent infestations, rust, etc resulting from the 
typical garage/barn/shed/basement storage that we've seen over and over, 
has impacted my opinion of private collections.

-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA


These are all valid concerns, especially since some collectors generally 
have eyes bigger then their belly, wanting more machines than they have 
the appropriate storage for. I fear i have been just as guilty (though i 
generally keep anything of value outside of the rat infested shed)




However, there are a great many people who do try and keep their 
collections indoors and on display. Obviously, this is much easier with 
machines like the 80's micros than it is with 60's and 70's big iron and 
minicomputers, which is likely the reason (plus larger production 
volumes) that so many machines of the 80's and beyond survive and are 
relatively plentiful.



It's also rather unfair to defame private collectors. A lot of them 
(especially the ones that come out of barns, leaky sheds, garages and 
basements) were the ones who saved the equipment from the scrappers in 
the first place. Much of this large system equipment survives (maybe in 
poor condition) purely because of the private collector. I believe that 
whilst climate controlled museums are ultimately the best place for 
functional equipment (where knowledge and skills can easily be pooled), 
the private collector has an important role in the preservation of 
equipment as well.


Cheers,

Josh Rice

Re: Does anyone/museum test disk packs?

[Joshua Rice via cctalk]

-- Original Message --
From: "Bill Gunshannon via cctech" 
To: cctalk@classiccmp.org
Sent: Thursday, 17 Mar, 2022 At 14:32
Subject: Re: Does anyone/museum test disk packs?
On 3/17/22 09:33, Chris Zach via cctalk wrote:
Modern disks still have a filtration system and airflow within the disk. 
Air usually gets sucked from the edge then through the spindle and out 
the center. In this case I think the spinning created a lower pressure 
area where the heads were, resulting in the heads flying too low.
I'll re-look at the RL02 but I believe air was not pulled in from 
outside but recirculated from behind the heads under the unit to the 
center spindle where it came out, into the center of the pack and across 
the heads. Closed system when the lid was closed.

No RL disk I ever had closed tight enough to be considered a Closed
System with lid down.  :-)
bill


That's worth noting. I have one that's in dire need of restoration, with 
a sizable chunk missing off the lid by the back hinges. Makes me less 
worried about fixing it with tape and cereal boxes

Cheers,
Josh rice

Re: 11/83 operating system load update -2

[Joshua Rice via cctalk]

> On Feb 23, 2022, at 6:04 PM, Chuck Guzis via cctalk  
> wrote:
> 
> If running 98 or 95, just do a "shutdown to MS-DOS prompt", rather than
> opening a DOS Window and you'll be fine.
> 
> --Chuck
> 

I’ve written RX50’s to generic PC SSDD disks using a DOS window in 98SE. As 
long as you’re running 9x, PUTR should work as intended. 

I highly suspect the issue lies with either the floppy controller, or the 
floppy drive itself. It would be worth inspecting the floppy drive to make sure 
lint or other detritus isn’t blocking the write protect mechanism. I had 
similar issues with the RX50 in my 11/23

Josh Rice.

Re: Installing an operating system on the 11/83 - update.

[Joshua Rice via cctalk]

I have a generic 5.25” (not sure of brand) in my dell GX1 but it writes plain 
SSDD floppies in RX50 format no problem. 

The RX33 was a pretty standard PC floppy drive AFAIK, just configured (with 
jumpers) to work as an RX33. You may find better milage configuring it as a PC 
floppy drive, as PUTR expects to work on PC drives at the device level. Having 
a real RX33 might be throwing it off. Don’t take it as gospel, since i’ve not 
got an RX33 to test it with.

Not sure if PUTR can copy images to a floppy, as i’ve only used it to build a 
bootable RT11 disk, and make a few RT11 disks out of the contents of images 
mounted by PUTR. You might find it better to work on a blank formatted floppy 
and build up from there.

> On Feb 22, 2022, at 4:20 PM, Rod Smallwood via cctalk  
> wrote:
> 
> Hi All
> 
>   I did find some RX50 images of the MicroRSX distribution.
> 
>  So I fired up my DEC Celebris FX. It runs W95 and has a 3.5 inch floppy, 
> a real RX33 5.25 inch drive and a CD-R.
> 
>Its accessible on my network so getting files onto it is not a problem.
> 
> So install putR.com , and transfer the image files.
> 
> Huh! putR says the RX50 disk is write protected. Its not and the drive 
> works normally with the disk from the MS DOS prompt.
> 
>  So much for putR writes RX50's on RX33!
> 
> Rod
> 
> 

Re: Origin of "partition" in storage devices

[Joshua Rice via cctalk]

This reminds me of the swapping/paging area in Windows 95/98 (maybe 
other
versions too), which was kept in a file, and therefore might be 
scattered all
over the physical disk. (Norton disk optimizer would coalesce the 
swap/paging

area to a contiguous area of the disk.)
Noel


Windows still uses a pagefile, even today, on NT systems.

There's several advantages to doing it that way, including balancing 
wear on a disk (especially today, with SSDs), as a dedicated swap 
partition could put undue wear on certain areas of disk. It's also much 
easier to dynamically allocate more (or less) swap space as is needed, 
which was very important in the days when RAM was expensive and very 
limited in quantity.


Of course, doing it that way has many disadvantages, not least the 
fragmentation issue (which was the root cause of much periodic slowdown 
on Windows machines in the mid 00's), but also the overheads involved 
with transferring rather scattered and unorganised RAM contents into 
nice, neat blocks understood by the filesystem. Though i have no numbers 
to back up my claims, i'm sure the overheads involved in translating RAM 
contents to a file was much more significant than just dumping the RAM 
contents into a SWAP partition.


Josh Rice

Re: Memory Tech you don't see very often

[Joshua Rice via cctalk]

Not cost effective at nearly $10,000! I understand they're very rare, 
given they were only used for a few years in industry and they're 
clocking on 3/4 of a century old, but even then, that seems an order of 
magnitude or two off the real value.
Actually, looking them up, doesn't seem they were used in much at all. 
Seems to have been a bit of a technological dead-end since core memory 
quickly superseded it with it's (relatively) cheap costs and (relative) 
ease of manufacturing. I imagine the US gov. probably used them 
somewhere, since they were a sucker for cutting edge technology of the 
time.

Would be interesting to know how many hours it's got on it

-- Original Message --
From: "pbirkel--- via cctalk" 
To: "'General Discussion: On-Topic Posts'" 
Sent: Wednesday, 5 Jan, 2022 At 17:35
Subject: Memory Tech you don't see very often
Selectron Vacuum Tube: https://www.ebay.com/itm/174977901251 



Really nice photo-shoot! I wonder what the back-story to this particular
tube might be.

I don't think that $16.18 shipping would be, um, adequate protection by 
any

measure.
Cheap, but not so sure about "cost-effective" .

-

Re: Cheap PDP-8 boards on eBait

[Joshua Rice via cctalk]

Looks like the seller has also listed a Lisa CPU board. I imagine that 
will be of interest to many here

RE: Looking for someone in London (UK) to read 2 9 track tapes

[Joshua Rice via cctalk]

The Centre for Computing History in Cambridge might be able to help too.

-- Original Message --
From: "Dave Wade G4UGM via cctalk" 
To: "'Chuck Guzis'" ; "'General Discussion: On-Topic 
and Off-Topic Posts'" 

Sent: Wednesday, 1 Dec, 2021 At 09:42
Subject: RE: Looking for someone in London (UK) to read 2 9 track tapes
Chuck,
I think TNMOC can read these tapes.
https://www.tnmoc.org/ 

Dave
-Original Message-
From: cctalk  On Behalf Of Chuck Guzis 
via

cctalk
Sent: 30 November 2021 23:57
To: CCtalk 
Subject: Looking for someone in London (UK) to read 2 9 track tapes
Hey list,
I received a note today from a fellow in London who has 2 9-track tapes 
that

he'd like read.  Brands are CDC and BASF, so media shedding should
not be a problem.   Dates are '92 and '93, so likely 1600 or 6259.  The
tape seal on one (the other has no seal) is IBM-style, which may be the
system that produced the tapes.
Any takers?  Let me know if so, I'll put you in contact and you can take 
things

from there.
All the best,
--Chuck

Re: Looking for info on memory

[Joshua Rice via cctalk]

-- Original Message --
From: "Nigel Johnson Ham via cctech" 
To: "Jerry Weiss via cctech" 
Sent: Thursday, 21 Oct, 2021 At 01:10
Subject: Re: Looking for info on memory
Thanks for that, but unfortunately it is crashing into ODT and not
accepting input from the console, which I remember was a symptom of no
bank 0 memory.
Now,of course, it could be the receiver chip in the J board (I used to
make a lot of money changing them ) but I have tried two separate J 
boards.

Of course if it is 4 MB, it must be in bank zero.
cheers,
Nigel



I've not had any experience with third-party Q-BUS modules, with nearly 
all my PDP-11's being built out of DEC cards, purely for the reason that 
documentation is easy to find. However, one thing i do remember reading 
up on is this: "NOTE WELL: For reasons which seem utterly 
incomprehensible, many boards designed for Q/CD slots (such as PMI 
  cards) do not 
avoid the QBUS pins on the CD connectors which contain 'hazardous' (to 
TTL circuitry) voltages. Plugging such a card into a Q/Q backplane will 
generally destroy the card." https://gunkies.org/wiki/QBUS#Backplanes 
 .



Some of the later quad-height DEC memory modules had either jumpers or 
resistors/fuses/not-sure-what-they-are that could be snipped out to 
convert between Q/Q and Q/CD slots. I've seen this on MSV11-P cards. 
It's entirely possible that the card wasn't configured correctly, and at 
some point got fried by the mismatch between Q/CD and Q/Q.


I would definitely recommend obtaining another memory board and swap it 
in. Smaller capacity QBUS memory boards are usually quite cheap and 
plentiful, so getting a 64K/128k card isn't impossible and won't break 
the bank. It would at least help diagnose if it's the memory board, or 
if the issues are deeper seated in your backplane or CPU module.


I would also add, make sure your backplane is clean and not damaged. 
It's an easy thing to overlook, but corrosion, damaged traces, damaged 
pins, and general detritus can lead to all sorts of funky malfunctions.


Cheers

Josh Rice

Re: Computhink Eagle 32 - software, docs, info?

[Joshua Rice via cctalk]

> On Oct 17, 2021, at 4:33 PM, Jules Richardson via cctalk 
>  wrote:
> 
> 
> Hey all,
> 
> Someone in one of the Facebook vintage groups that I'm in just picked up a 
> Computhink Eagle 32, an early-ish (appears to be circa 1981/82) 68000-based 
> machine with integral display and keyboard.

I saw that exact thread, and was as intrigued as you. Looks like it didn’t have 
any graphics capability, but instead had a text-based terminal built in. Quite 
unusual to see such a basic machine with such a capable CPU.

Here’s an imgur URL to the pictures, for anyone not in the facebook group: 
https://imgur.com/gallery/8cFyA7p 

Here’s the link to the facebook post: 
https://www.facebook.com/groups/vintagecomputerclub/posts/5038930992806893/

Cheers, 

Josh

Re: ISO M100, M102, M633 flip chips for DEC TC08N controller

[Joshua Rice via cctalk]

-- Original Message --
From: "Josh Dersch via cctech" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Friday, 1 Oct, 2021 At 08:33
Subject: ISO M100, M102, M633 flip chips for DEC TC08N controller
Hey all --
I have a TC08 DECtape controller that I'd like to convert to a TC08N 
(the
negibus version of the TC08). If I'm reading the documentation right, 
this
involves swapping in a few flip chips -- M100 for the installed M101, 
M102

for M103, and M633 for M623.
If anyone has any of these, please drop me a line. Curious also if 
anyone
out there has done this conversion and can comment on whether my 
assessment

is correct...
Thanks!
- Josh

I might be preaching to the choir here, but if you can't find originals, 
this website is an absolute goldmine for flip-chip schematics. If you 
can find the components (or modern equivalents) it might be worth making 
your own.


https://so-much-stuff.com/pdp8/flipchip/Mxxx.htm 



Josh Rice

Re: PDP-11/05 Fault?

[Joshua Rice via cctalk]

-- Original Message --
From: "Jerry Weiss via cctalk" 
To: "Paul Koning" ; "General Discussion: 
On-Topic and Off-Topic Posts" ; "Nigel Williams" 


Sent: Thursday, 30 Sep, 2021 At 15:08
Subject: Re: PDP-11/05 Fault?
On 9/30/21 8:12 AM, Paul Koning via cctalk wrote:
On Sep 30, 2021, at 1:02 AM, Nigel Williams 
 wrote:

On Thu, Sep 30, 2021 at 10:49 AM Paul Koning via cctalk
 wrote:
I see that the PDP-11 architecture handbook doesn't seem to be on 
Bitsavers...

Do you mean this handbook?
http://wwcm.synology.me/pdf/EB-23657-18%20PDP-11%20Architecture%20Handbook.pdf 


ORDER CODE: EB-23657-18
(from here: http://wwcm.synology.me/scanned.html 
 )
Yes, that's the one.  Excellent reference, it's the only place where 
I've seen that entire large tables (52 entries) of model differences.

paul

The same table is also in EK-DCJ11-UG-PRE_J11ug_Oct83.pdf.  I find the 
latter just a bit easier to read.

   Jerry


That book multiplies like rabbits though. I swear, any time i buy any 
new PDP-11 literature, i somehow end up with another copy. They're not 
that rare (or maybe i'm just lucky)



Josh

Re: An American perspective on the late great Sir Clive Sinclair, from Fast Company

[Joshua Rice via cctalk]

Commodore in the USA/CANADA was often pressed into service for a cheap
text video overlay for broadcast TV. Was that TV overlay ever used in
the UK or Europe?
Ben.


In the UK, Acorn gear was used quite a bit for overlays and computer 
generated graphics. I think the Amiga was used to a certain extent in 
commercial and small-enterprise video production, but the BBC almost 
exclusively used RISCPC and BBC Micro's for their graphics.






The Centre for Computing History (a Cambridge based museum) did a great 
video on the old Acorn broadcast gear used by the BBC



https://www.youtube.com/watch?v=exW-LbLRJV0 




Josh Rice


Preview external media

Re: Linux and the 'clssic' computing world

[Joshua Rice via cctalk]

Claiming one OS is better than another is always a contentious issue, 
and i'd rather prefer that this mailing list didn't fall for the same 
petty bickering that can be found across the internet. The fact of the 
matter is, when it comes to emulation on x86 IBM PC compatibles, both 
Windows and Linux are on a pretty level playing field, with most 
emulators available on both platforms. Obviously, there's more hardware 
platforms that support Linux (like the RPi and other ARM boards), and 
many retro collectors use such ARM based systems for emulation. However, 
much of the "Linux" software is in fact POSIX software, and can quite 
easily be ported between Linux and other *NIX-likes, such as Solaris, 
macOS and the *BSD family. As such, with a bit of time and effort, most 
of the emulators are fairly hardware-agnostic and can be ported to 
anything with a POSIX interface, opening them up to be ported to 
whatever hardware and software platform your heart desires.


Josh Rice

VT101 parts available, found on Reddit

[Joshua Rice via cctalk]

Someone on Reddit has found much of a VT101 and would like to rehome it. 
Not sure where he's located, but somewhere in US
Thread is here: 
https://www.reddit.com/r/vintagecomputing/comments/ogy6im/so_i_found_a_vt101/

Re: DEC PDP-8/e H212 core mat repair

[Joshua Rice via cctalk]

-- Original Message --
From: "Tom Hunter via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Monday, 19 Jul, 2021 At 06:33
Subject: DEC PDP-8/e H212 core mat repair
I am curious if anyone has attempted to repair (replace) a broken wire 
in a
PDP-8/e H212 (MM8EJ) core mat (8 k word). The cores are not visible 
without
a microscope. I cannot imagine how these were even manufactured and 
wonder

if DEC service centers repaired core mat faults or if faulty boards were
simply discarded.
CDC 6600 cores were huge in comparison and I would not hesitate to 
replace

a broken core wire on those.
Best regards
Tom Hunter


These patents might be enlightening. I'm sure there's others, but these 
are some i've found on a quick search.
https://patents.google.com/patent/US4161037A 

https://patents.google.com/patent/US3668664 


Josh

Re: DEC PDP-8/e H212 core mat repair

[Joshua Rice via cctalk]

-- Original Message --
From: "Tom Hunter via cctalk" 
To: "General Discussion: On-Topic and Off-Topic Posts" 


Sent: Monday, 19 Jul, 2021 At 06:33
Subject: DEC PDP-8/e H212 core mat repair
I am curious if anyone has attempted to repair (replace) a broken wire 
in a
PDP-8/e H212 (MM8EJ) core mat (8 k word). The cores are not visible 
without
a microscope. I cannot imagine how these were even manufactured and 
wonder

if DEC service centers repaired core mat faults or if faulty boards were
simply discarded.
CDC 6600 cores were huge in comparison and I would not hesitate to 
replace

a broken core wire on those.
Best regards
Tom Hunter


I believe much of the core manufacturing for DEC minicomputers was 
outsourced, but a lot of it had become much more automated by the late 
60's and early 70's. I believe it was done by machine, with a tray to 
hold the toroids in place, and a very fine needle-like "bobbin" that 
threaded the wires through the toroids. I believe threading the cores by 
hand had become largely obsolete by the time the PDP-8 came onto the 
market.
Though i can't confirm it, i highly doubt that DEC engineers would 
repair core planes. These would more likely be sent back to the 
manufacturer for "recycling", with the cores being recovered and reused.
It's worth noting that most computer manufacturers appreciated the 
fragility of core memory planes at the time, with most of them being 
protected with either PCB's or perspex/plastic shields on top of the 
core planes. In this way, it was rather difficult for a clumsy ol' 
technician to put his thumb through the planes as he was servicing 
machines.

Josh

Re: MOPPY.....

[Joshua Rice via cctalk]

You missed my favorite...
https://www.youtube.com/watch?v=GNTtR6ZpUOo At Doom's Gate (Doom 
soundtrack)

Cheers
Josh Rice

Re: QBUS/UNIBUS card handles

[Joshua Rice via cctalk]

On May 10, 2021, at 8:48 AM, Tom Hunter via cctalk 
 wrote:


 Just don't expect it to be as tough as the original.


I would assume it would be trivial to do an injection-moulded run of 
these handles, if 3D print schematics are available. They were 
definitely well-copied in the hey-day of the PDP-11, with most 3rd-party 
cards using identical handles, minus DEC branding.
I think the real question would be if doing a production run would be 
worth it. To make it economical, you'd need to do a run of a few 
thousand, but i can't imagine the market demand would be there for so 
many handles. The other question is, why replicate the originals? 
Surely, there's got to be a drop-in replacement that would be stronger, 
even if it's a length of bent steel rod with the ends flattened and 
drilled through. (I'm sure i've seen someone do this somewhere, but i 
may have just dreamed it)

Josh Rice

Re: DEC LK201-AA removable feet dimensions?

[Joshua Rice via cctalk]

If it’s of any assistance, i have one too. I see you have measurements, but 
here’s some photo’s which may also help

https://imgur.com/gallery/jWIR3F2

Cheers, 

Josh Rice

> On Apr 25, 2021, at 1:39 AM, Seth Morabito via cctalk  
> wrote:
> 
> On Mon, Apr 19, 2021, at 6:19 PM, Rick Murphy via cctalk wrote:
>> Height 27.38 mm (1.07 in)
>> Diameter 13.36 mm at the base (closed end), 13mm at the open end (hard 
>> to measure as it's easily deformed).
>> Ear slots 5.5 mm wide
>> Ears 2.17 mm wide, 11.3 high (the tooth-shaped part only).
>> -Rick
> 
> Thanks so much, Rick, I greatly appreciate it! I'm going to try building one 
> in OpenSCAD and printing them out. I'll let the list know how it goes.
> 
> -Seth
> -- 
>  Seth Morabito
>  Poulsbo, WA
>  w...@loomcom.com

Re: FTAG: AlphaServer DS15, Sun T5140, Sun Blade 10, HP Proliant DL380 G7, VT220 [London, UK]

[Joshua Rice via cctalk]

I'd be more than willing to take the VT220 and bits, but it would be 
public transport for me, unless you fancy a day trip to the Dorset 
seaside. I've been looking for one of these reasonably priced for a 
while to go with my MicroPDP-11's


Otherwise i might be able to persuade my other half to let me go on the 
train next weekend. Looking at it, it doesn't seem too unreasonable, and 
those VT220's are small enough to get in a travel case.

Cheers,
Josh Rice


-- Original Message --
From: "Adrian Graham via cctalk" 
To: "Andrew Luke Nesbit" ; "General 
Discussion: On-Topic and Off-Topic Posts" 

Sent: Thursday, 22 Apr, 2021 At 09:08
Subject: Re: FTAG: AlphaServer DS15, Sun T5140, Sun Blade 10, HP 
Proliant DL380 G7, VT220 [London, UK]

Hi Andrew,
My Mrs will batter me, but if nobody steps up for the Alphaserver and 
VT220 I’m only a couple of hours from you so will gladly give them a new 
home.

Cheers,
--
Adrian Graham
Owner of Binary Dinosaurs, the UK's biggest private home computer 
collection?

t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

On 21 Apr 2021, at 13:27, Andrew Luke Nesbit via cctalk 
 wrote:

Hello all again,
With a heavy heart I need to find a new home for the following beautiful 
hardware:

-   AlphaServer DS15 server
-   Sun SPARC Enterprise T5140 1U rack server
-   Sun Blade 10 mini tower
-   HP Proliant DL380 G7 2U rack server
-   DEC VT220 with screen, keyboard, and various adapter cables
Please note that the Sun T5140 and HP DL380 are deep (700mm for purposes 
of installation in a rack).
I'm starting a new job next week and intend to focus on that and my 
family.  I've stopped working on various projects and I am vacating my 
studio workshop, so I have a lot of things to give away or sell.
The above items are all FREE FOR COLLECTION ONLY (a car will be fine to 
transport the above items).
I am located in London, UK.  Post code is N15 4QL (Seven Sisters and 
Tottenham Hale) in Haringey, London.

Kind regards,
Andrew

Re: PDP 11/23 for sale on Ebay

[Joshua Rice via cctalk]

-- Original Message --
From: "Jeffrey S. Worley via cctalk" 
To: cctalk@classiccmp.org
Sent: Wednesday, 21 Apr, 2021 At 16:18
Subject: PDP 11/23 for sale on Ebay
There's a nice, working PDP 11/23 with 20 meg hdd and 1meg (!!) of ram,

1MB RAM isn't exactly huge for a MicroPDP-11, though it's quite ample 
for a KDF11 machine. The most interesting thing about it is that it's 2 
512k M8067 boards, which from my experience are rather uncommon, and can 
fetch a pretty penny, as they're a bit faster than the M7551's.
I'm not sure why people are balking at the price though, $900 seems 
about right for a MicroPDP11, given how versatile and integrated those 
machines are. It's hard to get much more PDP11 in a smaller form factor, 
and having drives in the chassis itself really helps keep the space 
usage down. Much more practical than an 11/03 and pair of RL02's.
Looks like a really nice machine, worth picking up for those needing 
more PDP11's in their life.

Cheers,
Josh Rice

Re: Wagner WAC40

[Joshua Rice via cctalk]

> Very interesting looking.  I can't quite make out what is going on in that 
> rectangular area where all the wires terminate, labeled 0-15 and A-R.  Are 
> there diodes there?  Anything on the other side of that board?

Nothing but traces on the other side, though you’re right on them being diodes.

> The large cores with all the wires are remisniscent of core rope ROM.   If 
> so, I wonder if it's AGC (Lincoln Labs) style, EL-X1 style, or a scheme 
> different from either of those two.

It’s definitely some form of core rope ROM. 

Interestingly, the ferrite rings are built in pairs, with a "selection" coil 
wrapped around both, joining them. Therefore (i assume, i’m really no expert) 
they’ll be a positive pulse induced when passing through one coil, but a 
negative pulse when passed through the opposite coil. This probably helps in 
differentiating beween a 0, a 1, or a NULL state (ie 0v). 

I have no idea if that correlates with any particular format of Core Rope, but 
as far as my eyes can tell, that’  how the core rope is woven and functions.

I think, though again i’m no expert, that the termination points indicate that 
this read off a 16 bit word in parallel, instead of working in serial to build 
up a word. Therefore, it contains 16 (pairs of termination points) x 64 (pairs 
of “selection” rings) = 1 kiloword of storage. I may however, to quote Bob 
Geldof, be talking bollocks.

Josh Rice

Re: Looking for gnupro for BeBox BeOs PowerPC

[Joshua Rice via cctalk]

It may be worth contacting the Haiku OS project. They have quite a few old BeOS 
devs working on the project, i’m sure someone would know where to find a copy.

Josh

Wagner WAC40

[Joshua Rice via cctalk]

Hi, 

I recently bought a core rope memory unit from a Wagner WAC40, mainly because 
it’s very aesthetically pleasing and looks good on display: 
https://i.redd.it/h9sb550uhnm61.jpg 

However, i can fine very little about Wagner Computer, the WAC40 (and WAC12), 
or the man behind the company, Günter Wagner. Does anyone have any info on any 
of these subjects?

This links seems to be all i can find: 
https://blog.hnf.de/gauner-gelder-und-computer/

Thanks, 

Josh Rice

Re: Sovier/Russian 132-pin PGA Ceramic IC Packaging

[Joshua Rice via cctalk]

Though i’m no expert, it looks like those are more an artefact of production, 
rather than usable test points. It seems like those pins extend throughout the 
ceramic substrate, and were most likely produced by pushing the pins through 
holes in the substrate and then soldering them. This may have been a solution 
used when the factory making them had limited tooling, or the chip was 
particularly low volume and more dedicated tooling was uneconomical.

> On Feb 9, 2021, at 10:27 AM, Paul Birkel via cctalk  
> wrote:
> 
> In item https://www.ebay.com/itm/265045229011 I am curious as to whether the
> gold islands on the top-side are functional test-points giving electrical
> access to the underside pins?  Was there a clip designed to attach to the
> top-side of these chips for use in circuit analysis?  Was this design unique
> to Russian manufacture (I don't recall ever seeing this design previously)?
> 
> 
> 
> paul
> 

Re: Dec RQDX: What kind of chips on it?

[Joshua Rice via cctalk]

Sorry for the spam!

Here’s some high-resolution pics i took of the 2 and 3 for your viewing 
pleasure:

https://imgur.com/gallery/VJPW5YV

Re: Dec RQDX: What kind of chips on it?

[Joshua Rice via cctalk]

These links may help:

http://decvax.50megs.com/doc/rqdx/rqdx.html 
 

http://www.vcfed.org/forum/archive/index.php/t-47834.html 


http://web.frainresearch.org:8080/projects/pdp-11/diskcntl.php 
 

There’s definitely incompatabilities between the RQDX2 and RQDX3. They 
shouldn’t be assumed to be designed or act similarly, despite their names. The 
only similarity is that the RQDX3 can read the same floppy disks as the RQDX2 
formats.

Re: Dec RQDX: What kind of chips on it?

[Joshua Rice via cctalk]

I’m not sure where i read it, but i’m pretty sure the main “brains” of the 
RQDX2 is a T-11 (PDP-11 FALCON) chip, and that does the negotiations between 
disk and system. I don’t know if it’s the same for the RQDX3, but i’d suspect 
not, as the incompatabilities between the 2 and 3 are probably due to a 
controller redesign. Though i really am no expert when it comes to disk 
controllers, and barely qualify as an amatuer with QBUS PDP-11’s in general!

I have a suspected faulty, but never tested (water damaged) RQDX2 i have pulled 
from a MicroPDP-11/23 i have been restoring. I don’t know if it’s any use, but 
i’m sure i can let it go for a pittance as long as you’re located in the UK

> On Jan 4, 2021, at 10:40 PM, Chris Zach via cctalk  
> wrote:
> 
> Can someone check to see if a RQDX2 used the Western Digital chips to 
> interface to MFM drives? Reason I'm asking is the MFM emulator can identify 
> an RQDX3, and also a Pro/350 controller but this particular RD52 I have 
> (which was verified by me to run Digital Mumps) is reading as:
> 
> root@beaglebone:~/mfm# ./mfm_read -a
> Board revision C detected
> Found drive at select 3
> Returning to track 0
> Drive RPM 3525.4
> Matches count 36 for controller WD_1006
> Header CRC: Polynomial 0x1021 length 16 initial value 0x
> Sector length 512
> Data CRC: Polynomial 0x1021 length 16 initial value 0x
> Interleave mismatch previous entry 0, 9 was 1 now 0
> Selected head 8 found 0, last good head found 7
> Read errors trying to determine sector numbering, results may be in error
> Number of heads 8 number of sectors 18 first sector 0
> Unable to determine interleave. Interleave value is not required
> Drive supports buffered seeks (ST412)
> Disk has recalibrated to track 0
> Stopping end of disk search due to recalibration
> Number of cylinders 512, 37.7 MB
> 
> Thanks!
> CZ

RE: LCD screen repair

[Joshua Rice via cctalk]

You'll have a better idea than me, but it looked like the underlying 
glass in the LCD panel was cracked, though that might have been dust 
smudges.
If it's just the overlying plastic coating that's scuffed, it's possible 
to replace it, but quite tricky. I'm not overly familiar with the panel 
in question, but often there's several layers of plastic. One is likely 
a matte effect coating, and the one underneath is probably the polariser 
sheet. If it's the polariser that's gone (you can tell, because the 
damaged area where the polariser has gone won't have any colour, will be 
solid white), you'll need to very carefully replace that (in the right 
orientation!) without causing air bubbles or other artefacts in the 
process

If it's just the matte coating, just remove it, again very carefully.

Re: PDP-11 based Data Translation system on ebay

[Joshua Rice via cctalk]

> On Aug 15, 2020, at 6:21 PM, Zane Healy via cctalk  
> wrote:
> 
> On Aug 15, 2020, at 9:47 AM, Douglas Taylor via cctalk 
>  wrote:
>> 
>> Many of you have seen this on ebay already:  item 224117176901
>> 
>> I'm on the east coast so it is out of my reach.
>> 
>> It appears to be a complete Data Translation data acquisition system 
>> including the software!  Someone please rescue this!
>> 
>> Doug
> 
> Wow!  Anyone close to LA should definitely consider this.  I’m trying to 
> avoid more hardware, but I actually checked to see where in California it is! 
>  That has the potential to go for an amazing price, considering what’s in 
> that lot.
> 
> Zane
> 
> 

It looks like a good set of hardware. The only downside is the large quantity 
of non-DEC cards in there, which i’ve found to be rather difficult to find 
documentation for…

However, for the price, a pair of PDP-11/23’s isn’t a bad score. Not sure what 
you’d do with such a specialised rig though… but it’s an excellent bargain just 
as parts.

Re: : Unknown Intel blinkenlight panel circa 1973

[Joshua Rice via cctalk]

> On Jun 19, 2020, at 3:07 PM, Noel Chiappa via cctalk  
> wrote:
> 
> BTW, speaking of Intel PDP-11 memory, I have this:
> 
>http://gunkies.org/wiki/File:IN-1611.jpg
> 
> QBUS Intel memory board; hven't tried to get it running, though.
> 
>   Noel
> 

I have a similar M8044 DD PDP-11 QBUS board populated with Intel C2117 
gold-ceramic chips. Much like you, i’ve not tried powering it up. Intel memory 
chips were used in quite a few QBUS RAM boards.

Re: IBM vacuum tubes

[Joshua Rice via cctalk]

Hard to say, without the modules they came from. 

As far as my (limited) understanding of vacuum tube logic goes, double triodes 
were very common for implementing basic boolean logic functions. Therefore, 
most IBM vacuum tube computers and data processing machines would have 
hundreds/thousands of similar dual-triode tubes making up the logic. 

Basically, they could be out of any vacuum tube machine made by IBM. IBM 600 
and IBM 700 series machines being the most likely.

> On Jun 15, 2020, at 2:51 PM, Guy N. via cctalk  wrote:
> 
> While going through my assortment of old vacuum tubes looking for audio
> treasures, I found a handful of IBM branded ones.  Mostly 5965, but
> there's one 5963 mixed in.
> 
> These are dual triodes with the same pinout as common small-signal audio
> tubes such as 12AX7/7025/ECC83, but characteristics closer to 12AT7 or
> 12AU7.  My RCA Receiving Tube Manual says they're designed to withstand
> being held in cutoff for long periods of time, and mentions digital
> applications.
> 
> Anyone know what kind of IBM machine these would have been used in?

Re: : Unknown Intel blinkenlight panel circa 1973

[Joshua Rice via cctalk]

Somehow it seems the thread got fragmented. I posted it to the other half of 
this thread.

Here’s a link to a high-quality picture of the front panel, straight from the 
listing. Turns out i’m crap at taking steady photos

https://i.ebayimg.com/images/g/dysAAOSwqqJehZ-Y/s-l1600.jpg 


> On Jun 15, 2020, at 1:15 AM, Chuck Guzis via cctalk  
> wrote:
> 
> It would be useful if the legends on the panel were actually readable by
> mere mortals.
> 
> Intel Memory Systems was very big in the early-mod 1970s.  The reason
> was pretty simple--they offered add-on memory for IBM S/370 and other
> vendors cheaper than the OEMs could.
> 
> --Chuck

Re: Unknown Intel blinkenlight panel circa 1973

[Joshua Rice via cctalk]

PDP-10 was 36-bit. You’re thinking of the PDP-1, 4, 7, 9 and 15 line of 
computers. 

However, it’s not actually 18-bit, but 2 8-bit bytes with parity for each byte. 
If it is indeed an early Intel memory addon for minicomputers, i’d expect it to 
be for the 16-bit DG Nova or PDP-11 line of machines.

> On Jun 15, 2020, at 10:09 AM, Dave Wade via cctalk  
> wrote:
> 
>> 
>> -Original Message-
>> From: cctalk > > On Behalf Of Chuck Guzis via
>> cctalk
>> Sent: 15 June 2020 06:33
>> To: dwight via cctalk mailto:cctalk@classiccmp.org>>
>> Subject: Re: Unknown Intel blinkenlight panel circa 1973
>> 
>> On 6/14/20 8:41 PM, dwight via cctalk wrote:
>>> I can see why I was having problems. The picture was upside down. It
>>> looked like Spanish or something. Do remember that Intel's claim to
>>> fame wasn't just micro processor. They were one of the first to do MOS
>>> RAMs for big machines. They were more into solid state memory systems
>>> than uPs, until after the 8080. It clearly isn't for some
>>> 4004 or 8008. It was likely monitoring some RAM for some mini.
>> 
>> Intel Memory Systems Division was largely responsible for saving Intel's
>> bacon in the early 1970s.  The MPU business with the 8008 and  4004 wasn't
> a
>> moneymaker initially.
>> 
>> However, selling DRAM assemblies for various minis (e.g. DG and DEC) as
>> well as S/370 add-on memory amounted to a large portion of their early
>> sales.   IMSD was on the far end of Mathilda in Sunnyvale.
>> 
> 
> I found this ad here:-
> 
> https://books.google.co.uk/books?id=9Ih5WQ-muXEC=PT1=PT1=ibm/370+t 
> 
> hird+party+memory+intel
> 
> I think if we could read the legends on the front we might get a better idea
> of what system it was for...
> ... looks like 18-bits so something in the pdp-10 line?
> 
> Dave
> 
> 
>> Have a look at section 7 here:
>> 
>> https://johncargin.files.wordpress.com/2013/12/intel-catalog-1973.pdf 
>> 
>> 
>> --Chuck

Re: Unknown Intel blinkenlight panel circa 1973

[Joshua Rice via cctalk]

https://i.ebayimg.com/images/g/dysAAOSwqqJehZ-Y/s-l1600.jpg 


That’s off the listing.

Sorry the photos came out funny/upside down, i guess my phone couldn’t work out 
which way up it was…

I think the photos of the board numbers are clear enough in the IMGur link 
though. I can write them down if you wish. There’s no other markings on the PCB 
though, apart from the 3M printing on the raw PCB substrate

> On Jun 14, 2020, at 8:31 PM, dwight via cctalk  wrote:
> 
> Hi Al
> Can you repeat what the text is? I can't make out what it says, even with 
> magnification.
> Dwight
> 
> 
> From: cctalk  on behalf of Al Kossow via 
> cctalk 
> Sent: Sunday, June 14, 2020 9:21 AM
> To: cctalk@classiccmp.org 
> Subject: Re: Unknown Intel blinkenlight panel circa 1973
> 
> On 6/14/20 9:01 AM, Jon Elson via cctalk wrote:
> 
>> Any reason the picture is upside down?  Also, blurry, so it is hard to read 
>> the labels.
> 
> I can't find the original eBay listing right now.
> The pictures were better on there
> 
> 

Unknown Intel blinkenlight panel circa 1973

[Joshua Rice via cctalk]

Hi all. 

I recently bought a mystery blinkenlight panel. Closer inspection reveals it 
was manufactured by Intel in the early 70’s (1973), and some people on the book 
of faces suggested it was part of a “device multiplexer”(?)

I’m 95% confident it’s not strictly a “computer” blinkenlight panel, but rather 
an attached device, but that still hasn’t helped me narrow down what exactly it 
was from. 

I’ve not seen any early Intel stuff as rack-mount, so i’m wondering if it was a 
prototype, or maybe a piece of internal/non-commercial hardware for Intel's own 
use. 

I’m hoping someone here might be able to shed some light on this mystery.

Pictures: https://imgur.com/gallery/lD74oSy 

Thanks in advance.

Josh Rice

Re: Apple 1

[Joshua Rice via cctalk]

“Here i am, brain the size of a planet, and i’m controlling a robot that does 
tape backups”

> On Jun 14, 2020, at 6:28 AM, Al Kossow via cctalk  
> wrote:
> 
> On 6/13/20 10:20 PM, jim stephens via cctalk wrote:
>> Do they still have it?
> 
> The Y-MP was replaced by a cray-ette in the early 90s
> 
> In the end the main use for it was for doing backups
> with its tape robot
> 
> 
> 

Re: Thinking of selling my PDP's

[Joshua Rice via cctalk]

There’s ALWAYS a market for PDP-8’s and PDP-11’s. 

Sadly though, i assume these are all on the yankee side of the pond, ruling out 
the significant european market out entirely (and don’t even THINK about 
shipping, unless you want to remortgage your house)

Either way, i’m sure you won’t struggle to find a buyer. There’s plenty of 
online forums and message boards where collectors of all kinds of hardware 
frequent. If you’re adamant that’s you want to keep them from FleaBay (which, 
you never know, could garner a decent price as a public auction), it’s worth 
posting to some of the market forums, such as 
http://www.vcfed.org/forum/forum.php , 
and http://www.amibay.com/forum.php 

> On Jun 13, 2020, at 8:45 PM, kingcavespider 1 via cctalk 
>  wrote:
> 
> It sounds interesting, especially the pdp-11, but I don't know how shipping
> would work and it would be a long drive to try to pick up
> 
> On Mon, 25 May 2020 at 16:46, Charles via cctalk 
> wrote:
> 
>> I am getting closer to retirement (although not close enough) and I'm
>> considering selling off my PDP stuff, especially if I downsize and move.
>> 
>> Everything's working, but I just no longer DO anything with either
>> system... the adventure was acquiring all the pieces, fixing them and
>> learning the software :)
>> 
>> Anyhow I have an 8/A with cloned Programmer's Panel (Vince Slyngstad and
>> I made it around 2006) and limited function panel, 32K RAM board (also
>> have core), Philipp Hachtmann's USB interface board, RX01 floppy, two
>> RL02's, and a high-speed (optical) reel-to-reel paper tape reader. OS/8
>> is up and running. Several spare RL02 packs. It's all in a tall DEC rack
>> with an H-(something) power control box. The ASR-33 is not included, I'm
>> keeping that.
>> 
>> Also an 11/23+ (11/03 chassis) in a corporate cabinet with two RL02's, a
>> 16-line serial interface, VT-220 terminal. Also an RQDX3 which is
>> connected to a loose 3.5" TEAC floppy drive. Have RT-11XM, RT-11SJ and
>> TSX-Plus 6.50 (all 16 timesharing ports are working too).
>> 
>> So, I am wondering if there's any market for them (preferably as
>> complete systems). Shipping would be difficult due to the size/weight
>> (I'm in rural south central Missouri). I'm not looking to give them
>> away, or to part out, but would entertain reasonable package deals
>> rather than deal with the "LQQK! RARE!!" bull on ebay.
>> 
>> I can send pics to interested parties. Let me know,
>> 
>> thanks!
>> 
>> Charles
>> 
>> 
>> 

Re: Core Memory Photo

[Joshua Rice via cctalk]

Was beautiful.

That’s pretty mangled now.

> On Apr 14, 2020, at 5:53 PM, Fred Cisin via cctalk  
> wrote:
> 
> On Mon, 13 Apr 2020, keith--- via cctalk wrote:
>> "Ouch. Looks like that core took a serious hit." Yep it did.  We ran the 
>> microscope into it at the lab. Ouch. Someone had
>> asked for a picture of core memory without the cover so I thought it
>> would do.
> 
> It is beautiful!
> 
> 
> 

Re: pdp11/05 key?

[Joshua Rice via cctalk]

Late to the party, but there’s PDP11 keys sold on ebay here: 
https://www.ebay.co.uk/itm/DEC-PDP-8-PDP-11-Computer-Key-XX2247-Digital-PDP-8E-8I-8L-8S/333296145346?epid=2164686531=item4d99ff93c2:g:nWcAAOSwZtlZ7TIB
 


I’m 100% sure your local locksmith / cobblers / hardware shop can do it 
cheaper. 

> On Apr 7, 2020, at 2:04 PM, Noel Chiappa via cctalk  
> wrote:
> 
>> From: Ian McLaughlin
> 
>> I can confirm that about 6 months ago I gave this very information to
>> our corporate locksmith, and he was able to make a key for me that
>> works.
> 
> Thanks for the confirmation that that info is sufficient to produce a working
> key. I have updated the page to indicate that the info has been confirmed.
> 
>   Noel

Re: H7821 power supply in MicroVAX 3100, SCSI disk enclosures and others

[Joshua Rice via cctalk]

The main failure point of all old electronics are the capacitors. Over time, 
electrolytic capacitors dry out, and can cause a wide array of different 
faults. From ones that are leaky, and or way out of spec, they can exhibit all 
sorts of “fun” errors in hardware. 

The main one i’ve come across is “RIFA” brand rectangular thin-film filter 
capacitors. These can be quite violent when they fail, and they fail often. 
Many power supplies can be brought back (for a time) by just replacing these 
capacitors.

Electrolytics, whilst far more reliable (and less explosive) than the RIFA 
capacitors, also dry out and go bad over time. However, uness your machine was 
built during the “capacitor plague”, these can still be surprisingly reliable. 
However, if you’re planning on using the electronics regularly, they are still 
recommended to be replaced.The SMD electrolytics from the late 80’s and onwards 
 often need replacing,. These can leak and rot out the leads, and being surface 
mount, they can be quite tricky to replace.

Outside of electrolytics, tantalum capacitors can also fail. Whilst they don’t 
“dry out” as such, they still degrade over time. These can fail quite 
spectacularly, resulting in smoke and flames if you are not careful. They are 
generally more reliable, and probably not worth replacing across board, but 
when they do fail, it can be quite impressive.

Other electrical components, such as PCB’s, resistors, and silicon chips, have 
no discernable lifetime outside of corrosion and physical damage. Provided they 
are looked after, these components can carry on working indefinitely. 

Obviously, mechanical components (fans, relays, rotary switches), vacuum tubes, 
and much older cardboard tube components (resistors in vacuum tube TV’s/radios) 
stiff suffer from degredation from wear and old age. Often replacements can be 
as scarce as the equipment itself, so extra care should be taken when powering 
that sort of stuff on.


> On Jan 31, 2020, at 7:22 PM, P Gebhardt via cctalk  
> wrote:
> 
> Yep, that's what I call preventive electronics maintenance: I power up for a 
> little time at least once a year all electronics that were in operational 
> order up to a year ago, no matter what it is, to make sure they don't turn 
> defective from "non-running", which is mainly affected by caps indeed. 
> Best regards,
> Pierre

Re: Update: Shipping 50 lb computer from Zell am See, Austria to CA.

[Joshua Rice via cctalk]

I’ve had/am having a similar sized machine shipped from Bulgaria to the UK, 
twice. Board first, chassis second. It cost me roughly £60 all in.

I expect a machine taking that long a journey would be best done by ocean 
frieght. It’ll take longer than air mail, but a transatlantic flight with a 
machine that weight will cost a lot. 

If you have to get it air mailed, split it up into seperate loads. Shipping it 
in parts will cost less than one lot, and also reduce the risk of the whole lot 
being lost in the post. 

if you can, it’s probably more cost-effective to ship it in parts than as one 
whole lump. 

> On Aug 23, 2019, at 9:19 AM, steven stengel via cctalk 
>  wrote:
> 
> Well, I knew the computer, just not the city.
> 
> It's Zell am See, a small town in western Autria, far from everywhere it 
> seems.
> 
> The computer is a Datapoint 2200 - 50lbs, 10x19x20 inches.
> 
> I want to get it shipped to Calfornia, where I live.
> 
> The cheapest option is to just use local Austria mail, but max dimensions are 
> 60x60x100cm, or
> 23.5x23.5x40 inches. That would leave just 2-inches on each of two sides for 
> padding.
> 
> Best option - remove the plastic cover and mail it separately. Correct me if 
> I'm wrong, but the entire bottom of the computer seems to be a solid piece of 
> metal, like the Apple III = very strudy. The back is a giant metal heat sink.
> 
> I think it's do-able, do you?
> 
> Steve.

Re: Test

[Joshua Rice via cctalk]

> On Aug 11, 2019, at 3:25 PM, Alexandre Souza via cctalk 
>  wrote:
> 
> Test error. Please call helpdesk. 555-1212

Have you tried turning it off and on again?

Re: 11/93 Rebuild

[Joshua Rice via cctalk]

Same command will work from a linux live cd


> On May 27, 2019, at 9:30 AM, Rod Smallwood via cctalk  
> wrote:
> 
> Hi
> 
>   On an old XP box?  er neither will run
> 
> Rod
> 
> 
> On 27/05/2019 08:25, Christian Corti via cctalk wrote:
>> # dd if=RD54.dsk of=/dev/sda  [or whatever the device name is]
>> 
>> Oh, you said Windows... I'd recommend installing Cygwin ;-)
> 
> -- 
> 
>