Re: VAX 780 on eBay

[Mark J. Blair via cctalk]

> On Jan 2, 2022, at 4:20 PM, Chris Zach via cctalk  
> wrote:
> 
> On 1/2/2022 6:21 PM, Mark J. Blair via cctalk wrote:
>> I am seriously lusting after that VAX-11/780 system on eBay
> I keep thinking about it, but no. The 780 was neat from a historical 
> perspective, and the 785 at UMBC (UMBC5) ran Ultrix (and was on the ARPANET, 
> not the crappy Bitnet the 8600's were on) but the 780 was really slow. I have 
> a Microvax II here that would equal it CPU speed-wise, and the running of the 
> main memory on the SBI was cool for the 782 option but was pretty slow.

The VAX-11/780 may be very slow, but it is still still quite a bit faster than 
my 11/730. That being said, the 11/730 captures the look and feel of that era 
of VAX in a much smaller volume and with a lot lower energy cost.

> Now a Vax 8600 or 8650 That would be interesting. Partially due to the 
> Jupiter angle, partially because it was the fastest MASSBUS system with true 
> pdp11 compatibility.

Oh, heck yeah! I'd love to have an 8600 or 8650, and I would see them as the 
logical conclusion of the VAX-11/7xx line despite the model number change.


-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: VAX 780 on eBay

[Mark J. Blair via cctalk]

In the unlikely event that I win the lottery before that 11/780 batch sells, 
I'm going to buy it, buy a box truck, go pick it up, and then leave the box 
truck parked outside while I build a new building to put it all in. :D

-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: 11/785 on ebay (2018) - was Re: VAX 780 on eBay

[Mark J. Blair via cctalk]

> On Jan 2, 2022, at 1:03 PM, Toby Thain via cctalk  
> wrote:
> 
> On 2022-01-02 2:48 p.m., Noel Chiappa via cctalk wrote:
>> > From: Jonathan Chapman
>> > Last one that went auction-style on eBay went for $1,178.00
>> When was that?
>> Do you have any details of the machine's config?
>> That's a pretty good deal for a 780 (IMO).
> 
> Someone I know won a '785, Feb 10, 2018, but it went for $1,000 (they bid 
> $1,178.50).

HAHAHA! I love their bid amount. I can remember that I paid $1,575.42 (+tax 
etc.) for my T368C transmitter, because I was working in the GPS industry at 
the time, and I bid the GPS L1 frequency in MHz. The second bidder just missed 
outbidding me, and I got it for my maximum bid.

-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: VAX 780 on eBay

[Mark J. Blair via cctalk]

The poles supplying my rural property just have one phase of 12kV on them, so 
even if SCE was willing to provide 3ø service to me, I bet it would be 
*expensive* to get the whole line upgraded to 3ø service all the way up to the 
last pole with all three phases present. I think that's probably within a mile 
or so, but that's still a bunch of poles to be upgraded. I use a rotary phase 
converter to feed my milling machine and lathe. If all three phases were on the 
pole already, I probably would have asked about getting 3ø service when I built 
on my property. But with just one phase on the poles, I didn't bother asking.

They did just replace those overhead wires and some poles for fire prevention, 
and in the process they put in a whole great big pole-mounted switch that can 
be flipped from ground level just for my service disconnect, and another one 
for a neighbor's disconnect. It looks like they installed a regular 3ø 
disconnect switch, but only two of the wires are present and one switch pole is 
not connected. My service transitions from overhead to buried at that pole, and 
is buried for the last 100' or so to my ground-mounted transformer.

Two of the poles they replaced were in the easement just on the other side of 
my property line. The contractors were happy with my cooperation in giving them 
access to my property so they could put trucks on both sides of the fence line. 
I also handed out 15 60mm ammo cans from my stash, since I like contractors on 
my property to be happy. So, they conveniently forgot to take the two old 45' 
poles they replaced with them at the end of the day, and I won't have to buy a 
new ham radio tower after all. ;)

I am seriously lusting after that VAX-11/780 system on eBay, but I just don't 
have the available indoor space for it, or a big enough pile of cash to buy it 
and then spend enough to give it a good home. I'm glad that it's not in 
southern California, because if it was within an hour or two of driving I don't 
think I'd be able to resist the temptation. I do have my nice little 11/730 
already. I'm eying the UNIBUS expansion bus from that seller to add to my 730, 
but I think should leave it available for the buyer of that 780.

-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: tamayatech let down

[Mark J. Blair via cctalk]

> On Dec 26, 2021, at 10:00 PM, Chuck Guzis via cctalk  
> wrote:
> 
> I got a kick out of the eBay sellers flogging logic analyzers without
> the pods, advertising them as "working".  How can you tell?

I guess that at least reveals sellers whose item condition statements cannot be 
trusted.


-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: PDP-11/44 gas struts

[Mark J. Blair via cctalk]

Like Steve, I don't know about the original application. My own 11/44 project 
pile has the slide out and rotate style of slides, to the extent that it has 
any slides at all. When I need gas struts and cannot identify a source for 
exact original replacements, I usually look at McMaster-Carr first:

https://www.mcmaster.com/gas-struts/

-- 
Mark J. Blair 
Blog:https://www.nf6x.net
Git: https://gitlab.com/users/NF6X/groups
HECnet:  DOGPAK::MBLAIR
Twitter: @nf6x

Re: DEC BA11-K KY11-L mounting brackets -- how?

[Mark J. Blair via cctalk]

I'm not at home with the machine now, but if I remember (or get reminded in the 
next day or three), I'll try to take some pictures of my PDP-11/34A to help you 
out.

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

Re: Looking for VAXSET Software Engineering Tools for VMS 4.x

[Mark J. Blair via cctalk]

> On Apr 16, 2021, at 11:38 AM, Malte Dehling via cctalk 
>  wrote:
> 
> Whether VAXSET is on there or not, I would be very interested in ISOs of
> both of these either way!

If Antonio does not mind sharing them a bit more widely, I would also like to 
have ISOs of them. I'm interested in running earlier VMS versions on my 11/730.

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

Re: misc stuff - free

[Mark J. Blair via cctalk]

> On Dec 15, 2020, at 11:09 AM, Johan Helsingius via cctalk 
>  wrote:
> 
> This is one of the reasons why I miss good old USENET - with a public list
> of groups, and a clear hierarchy.


USENET is still around. But much like the rest of the infinite groups, it's not 
where everybody is. Sigh.


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

Re: VT-320 interfacing

[Mark J. Blair via cctalk]

> On Nov 9, 2020, at 5:53 PM, Grant Taylor via cctalk  
> wrote:
> 
>> The VT320 only has the DEC-423 MMJ, no RS-232.
> 
> I /thought/ that Modified Modular Jack was simply a physical thing and 
> completely independent of Recommended Standard 232.

DECconnect (aka MMJ) interface uses RS-423 electrical signaling, but it is 
compatible with RS-232 signaling aside from (I think) some reduced noise 
immunity over long lines when not using differential receivers.

The official DEC H8571 DE9 to MMJ adapter is just a plain pinout adapter which 
grounds the TX- and RX- signals and doesn't bother with differential signaling. 
It drives DSR, CTS and CD on the PC-compatible end with DSR from the MMJ 
interface. At the moment, one of our friends here has one for sale on his Etsy 
store:

https://www.etsy.com/listing/875566987/dec-h8571-de9-to-mmj-terminal-serial

Here's a page with details, including the wiring of that H8571 adapter:

https://www.lammertbies.nl/comm/cable/dec-mmj#h71j


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

Re: Unable to download Dave Dunfield's ImageDisk

[Mark J. Blair via cctalk]

> On Mar 25, 2020, at 9:22 AM, Seth Morabito via cctalk  
> wrote:
> 
> On Wed, Mar 25, 2020, at 4:47 AM, Dave Dunfield via cctalk wrote:
>> 
>> Should be fixed now - may have to refresh your browser if It cached
>> the bad links.
>> 
>> Dave
> 
> By the way, Dave, I just wanted to say thanks for ImageDisk. I use it 
> constantly on my floppy archiving box and it's one of the most important 
> tools in my workflow. I've even used it to realign several floppy drives with 
> great success. I truly appreciate your work on it.


Agreed! It's great. Even when I don't use it directly, the ImageDisk file 
format is good for a lot of stuff I do, such as archival of non-copy-protected 
disks for machines like the various Tandy/Radio Shack systems in my collection. 
I wrote Python code for working with the .IMD files on my Mac.

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

Re: [HECnet] VAX/VMS 3.0 Distribution Available for Download --> Decnet

[Mark J. Blair via cctalk]

> On Mar 21, 2020, at 7:20 AM, R. Voorhorst via cctalk  
> wrote:
> 
> It looks there is some decnet on the disk.
> Exec list gives phase-III router:

Which VMS release introduced DECnet Phase IV?


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

Re: PDP - 8 Front panels

[Mark J. Blair via cctalk]

> On Nov 28, 2019, at 2:40 AM, Rod Smallwood via cctalk  
> wrote:
> 
> Hello Everybody
> 
>  After a two year pause due to my wife having been ill but now fully 
> recovered I am back to starting making pdp-8 front panels again

Welcome back!


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

Re: flux to imd

[Mark J. Blair via cctalk]

The list isn’t broken. This thread started off-list, and the Chuck CC’d the 
list late in the thread. 

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

TU58 Archival (Was: Re: Tektrionix VAXBI board and DC100 training tapes?)

[Mark J. Blair via cctalk]

> On Sep 21, 2019, at 12:17 PM, Mattis Lind  wrote:
> 
> I dumped some 40 TU58 tapes a year ago. I replaced the band directly with 90 
> mm plastibands without even trying to run the tape. This was my procedure: 
> Open up the tape cartridge. Then the old band was removed carefully by 
> heating it slightly with a heat gun (low temperature). Then I managed to 
> remove it without destroying the tape itself. One can see the tape changes 
> appearance on the surface, then it can be removed. (Thanks to Rik Bos for the 
> advice about heating)


Thank you very much for your detailed instructions! I've tried using 
plastibands from a Baumgarten assortment once but it didn't work for me. I 
think the ones I used were the wrong size. They were very narrow once stretched 
into place, and they wouldn't stay on the tape reels without slipping off and 
terribly tangling everything up.

Coincidentally, I just got a food dehydrator for baking magnetic media before 
archiving, to prevent oxide shedding. I'll be using it for 8" floppy diskettes 
first. Does it matter whether baking is done before or after unsticking the old 
band from the tape?


> There are usually some residue from the band left on the tape. I used 
> isopropanol to remove this by gently rubbing the surface. Sometimes some kind 
> of salty residue has deposited on the back of the tape. Usually at the posts. 
> This was also cleaned gently using isopropanol. Failure to do the last step 
> usually caused the tape to stick during tape winding. Then cleaning the 
> backside helped out. 


Is cyclomethicone lubricant helpful for imaging old edge-driven cartridges like 
TU58, QIC, etc., or does it interfere with the belt drive?


> The bands I used was the 90 mm baumgarten plastibands. The interesting thing 
> is that they are actually japanese made by Nisshinbo and are called mobilon 
> bands. 
> 
> It should be possible to buy from Misumi. 
> 
> https://us.misumi-ec.com/vona2/detail/223000860382/?KWSearch=Mobilon=results2products=%7b%22field%22%3a%22%40search%22%2c%22seriesCode%22%3a%3000860382%22%2c%22innerCode%22%3a%22%22%2c%22sort%22%3a1%2c%22specSortFlag%22%3a0%2c%22allSpecFlag%22%3a0%2c%22page%22%3a1%2c%22pageSize%22%3a%2260%22%2c%220161458%22%3a%22mig0001661601%22%2c%22fixedInfo%22%3a%22MDM0001617623122300086038211%7c12%22%7d=codeList
> 
> 
> 460 bands for 18 dollars is far better than buying those assorted packs from 
> Baumgarten. 
> 
> Haven’t ordered myself since they want that you have a  company to order. 
> Need to ask a friend to help out. 


I've ordered a bag of those Mobilon bands. I just typed in my name for the 
company name when I registered, and their site seemed happy with that.


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

Re: Tektrionix VAXBI board and DC100 training tapes?

[Mark J. Blair via cctalk]

> On Sep 21, 2019, at 11:19 AM, Al Kossow via cctalk  
> wrote:
> I've got over a hundred TU58s I need to look at some day as well.
> Fixed the pinch rollers on some TU58s a year or two ago, just too many other 
> things to do.

I have about a dozen TU58 cartridges which came with my VAX-11/730. I'd like to 
archive them (or even read them, for that matter), but so far I have had not 
had any success with repairing cartridge drive belts. I just hate those things. 
I have a feeling that I might have better results by building an open reel 
imaging drive where I transfer the tape media out of the original cartridge, 
abandoning the &$@#! drive belt concept. But that's going to be a fairly big 
project, so I haven't made progress on it beyond brainstorming so far.


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

Re: Tektrionix VAXBI board and DC100 training tapes?

[Mark J. Blair via cctalk]

> On Sep 19, 2019, at 12:45 PM, Mattis Lind via cctalk  
> wrote:
> 
> Then there were some DC100 tapes in a huge heap of TU58 diagnostic tapes
> for VAX-11/730 and  VAX-11/750 that looked different.
[...]
> BTW. What are the status of various 11/730 and 11/750 diagnostics on TU58.
> Are those already dumped? It takes some time to work with TU58 so if
> someone already done all this I might skip dealing with them.
> 
> I know of only one place that has TU58 dumps.
> http://iamvirtual.ca/VAX11/VAX-11-software.html

That's the only site that I know of, too. Please see to it that those tapes get 
archived! Especially the 730 ones, for my own selfish interests as a 730 owner. 
:)

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

Shugart-Interface 8" Floppy Diskette Drive Configurability

[Mark J. Blair via cctalk]

I've been contemplating a floppy diskette drive emulator with features to make 
it fit better into systems using 50-pin Shugart style floppy drive interfaces 
vs. the other emulators already on the market. Studying manuals for various 8" 
floppy diskette drives, I see that they generally provided a great deal of 
configurability. There are the myriad of jumper-selectable options which change 
drive behavior for compatibility with various computers. Then there are 
features like FM data separators which are present on some, but not all, 
drives. And then there are many documented "cut this trace, then bodge wire 
this signal to pin X of the edge connector" options for special purposes such 
as individual drive motor controls, simultaneous monitoring of all four drive 
ready signals, etc.

Since fully supporting all of the options I've seen documented would have real 
hardware cost and add complexity to the design, I'm wondering just how much of 
that configurability is really necessary. Which non-default options are really 
needed for system still in use and/or in the hands of collectors? Which were 
only ever provided for some obscure industrial system manufacturer, with no 
surviving systems in existence? Which were included just in case somebody might 
need them, but were never used in practice?

I'd appreciate it if anybody can provide insight into this, such as examples of 
systems which required non-omnipresent and/or non-default configuration options.

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

Re: TRS-80 Fireworks

[Mark J. Blair via cctalk]

> On Aug 28, 2019, at 2:07 AM, Guy Dunphy via cctalk  
> wrote:
> An extremely common problem with all old electronics from around that era.
> The mains filter caps are commonly 'RIFA' brand metalized polyester film,
> encapsulated in a clear-honey-coloured resin. 
> The problem is that the resin embrittles and shrinks with age, resulting in
> many small cracks. (And sometimes large pieces falling off.)
> The cracks let in moisture, which absorbs into the insulating film.

I suspect those notorious Rifa brand capacitors would not be so problematic if 
they had polyester film dielectric. But if I'm not mistaken, they don't; they 
have *paper* dielectric!

Aside from that one correction, I agree with everything else you wrote about 
the likely failure mechanism of these evil little rectangles of compressed 
smoke and fire.

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

Re: Pertec Interface Cable Length

[Mark J. Blair via cctalk]

> On Aug 10, 2019, at 1:57 AM, Dave Wade via cctech  
> wrote:
> 
>> 
>> I have a question about cable length - any electrical engineers in the house?
> 
> Its electronics, rather than electrical engineering. Electrical Engineering 
> is power distribution.

At least in the US, "Electrical Engineering" applies to both subfields. Same 
university department, same degree name, same generic title of "electrical 
engineer"; just different specializations. I presume from your remark that an 
"electrical engineer" in the UK would be an engineer who works in the field of 
power generation and distribution. What term is used there for an engineer who 
works in fields of general electronics?


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

Re: Announcing Cadetwriter

[Mark J. Blair via cctalk]

> On Aug 1, 2019, at 9:15 AM, Dave Babcock via cctech  
> wrote:
> 
> Cadetwriter is being released.  [Cadetwriter is the official name of our 
> general-purpose, Wheelwriter-based Computer Terminal.]  The public unveiling 
> will be at this weekend's VCF West at the Computer History Museum in Mountain 
> View, California. Attached is a flyer on the device.


I don't think that the flyer made it into the mailing list posting. From the 
text of your email, this sounds pretty cool.

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

Re: Scotch 777 "blue label" tape blues confirmed

[Mark J. Blair via cctalk]

> On Jul 20, 2019, at 9:38 AM, Chuck Guzis via cctalk  
> wrote:
> 
> your cleaning machine

I do not have a cleaning machine. Do you suppose a cyclomethicone applicator 
fabricobbled into the tape path of a tape drive might work?

I haven't encountered these sorts of issues in 9-track tapes yet, but I've 
certainly been frustrated with binder bleed and/or sticky shed when I tried to 
mess with a TK50 drive.


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

Re: WordPerfect 5.1+ for VMS

[Mark J. Blair via cctalk]

> On Jul 17, 2019, at 10:43 PM, Dave Wade via cctalk  
> wrote:
> I think even if you have the key it fails today. There was a thread recently 
> on comp.os.vms
> 
> Saying it expires after  days and theirs had just expired...

Oh, now that's just obnoxious. Requiring a license refresh every 27 years? It's 
ransomware, I say!


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

Re: DEC Purchase Specifications, particularly 23-000A9-01

[Mark J. Blair via cctalk]

> On Jul 17, 2019, at 3:56 PM, Eric Smith via cctalk  
> wrote:
> 
> I expect that 70ns doesn't meed the DEC purchase specification for
> 23-000A9-01, but unless we turn up a copy of the actual purchase
> specification, we won't really know. It seems likely that the purchase
> specification would have required 55ns, as that was a very common "slow"
> speed grade for bipolar PROMs.

Also, while bootstrap PROMs may not necessarily need anything faster than 70ns 
(I seem to recall seeing a comment in the M9301 docs about 70ns being the 
minimum speed, but I may have made that up), faster PROMs may have been needed 
in other places where they were used as logic gates.

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

Re: DEC Purchase Specifications, particularly 23-000A9-01

[Mark J. Blair via cctalk]

At 70ns, I can make the design pretty simple by using an EEPROM. I did some 
trial synthesis targeting a Lattice MachXO2 part, and I think I could get the 
speed down into the 20ns range that way, at the cost of a more complex board 
design and needing to use Lattice's synthesis tool to prepare programming data.

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

Re: DEC Purchase Specifications, particularly 23-000A9-01

[Mark J. Blair via cctalk]

> On Jul 17, 2019, at 1:20 AM, Paul Birkel  wrote:
> From some notes (origin misplaced!) you'll need a typical access time of
> 40ns from address, or 20ns from /CS:

Thank you! That rules out using a 70ns EEPROM, then.

I think I have a line on most of the bootstrap PROMs that I will need, but I'm 
still interested in the general problem of replacing defective bipolar PROMs 
and making new ones, when I can't just order blanks from Digi-Key.


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

DEC Purchase Specifications, particularly 23-000A9-01

[Mark J. Blair via cctalk]

I've been studying scanned documents for the M9312 UNIBUS bootstrap/terminator 
card because of reasons. They refer to Digital Equipment Corporation Purchase 
Specifications 23-000A9-01 and 23-000F1-01 for the PROMs, and I'm wondering 
whether those documents have been preserved anywhere? I'd love to see them.

Ok, about the reasons: My PDP-11/34A has an M9301-YF bootstrap/terminator card, 
which doesn't have bootstrap code for a couple of the newer devices I'd like to 
use in the system such as RL02 and emulated TU58. The newer M9312 card looks 
more flexible for changing out bootstraps than the M9301 series.

I'm working on getting my hands on an M9312, but I don't know yet whether I'll 
be able to get original PROMs for the specific bootstraps that I want. I 
haven't identified a trustworthy source for blank old-timey bipolar PROMs yet 
(and I'm not sure if I have a suitable device programmer for them), and I was 
thinking about making some sort of PROM emulations that I can swap around like 
they're going out of style. It would probably be helpful (and definitely 
interesting) if I could learn details about the original part specifications, 
such as what speed ratings DEC used. I don't have an M9312 in my hands yet, and 
I'm not yet sure about how rapidly the card performs its little 4-to-16 bit 
deserialization stunt.

If 70ns access time parts are sufficient for the M9312's PROMs, then I may 
design an emulation with a 5V compatible 28 series EEPROM. If they need to be 
faster, then I may need to do something fancier. Or maybe I'll find the 
original PROMs that I need and then get distracted and wander off. It may well 
be easier to design a replacement for the entire M9312 card than trying to 
emulate the individual 512x4 bipolar PROMs, but since when do I do anything the 
easy way? I sure wouldn't be playing with 40 year old computers if I was 
concerned with practicality and ease of use!

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

Re: Posting of set of boards from a data General nova 3 triple option

[Mark J. Blair via cctalk]

> On Jul 12, 2019, at 9:27 PM, Jeffrey Birkin via cctalk 
>  wrote:
> 
> I have a set of boards from a data General nova 3 triple option 
> Location: Vancouver Island Canada 
> If interested please email jeffreybir...@hotmail.com


I have a Nova 3 system, but I am not familiar with what the triple option is. 
Is it something I should lust after?

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

Emulex SC11 Documentation Wanted

[Mark J. Blair via cctalk]

I'm looking for documentation covering a board set which came with my new 
PDP-11/34A. It looks like an Emulex SC11 disk controller, but it appears to be 
a newer version than what is covered in the 1979 manual scan which I found on 
Bitsavers. I have pictures of the board set on my blog:

http://www.nf6x.net/2019/06/emulex-sc11-disk-controller-documentation-wanted/


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

Re: Recovering the ROM of an IBM 5100 using OCR (among other things)

[Mark J. Blair via cctalk]

> On Jun 27, 2019, at 8:21 AM, Warner Losh via cctalk  
> wrote:
> 
> Back when I got to school and I was hanging around the computer room on
> campus (back when it was THE room on campus with computers), I saw this
> half-dollar sized plastic fob on the desk and asked what it was for. The
> on-staff operator took a mag tape off the rack, opened it up and set the
> end of the tape on the table. She then took the fob and placed it on the
> end of the tape and all the iron filings that were suspended in the liquid
> inside the fob aligned to the magnetic fields of the tape.

I don't recall seeing one of those in either of the computer rooms I worked in 
as a student back in the late 1980s. I would love to get my hands on one (or 
make one?) now.

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

Re: Kids these days...

[Mark J. Blair via cctalk]

I wouldn’t invest in an IoT buzzword company whose web page admits that the 
products they are talking about don’t exist yet, headed by a non-engineer, even 
without the fishy international money laundering smell. It’s interesting how 
quickly you ferreted that out, William. I don’t have a clue about business 
stuff like that. 

Yesterday I saw a company car for a presumed IT service company called Telnet 
something or other. I don’t think I would rely on Telnet for my information 
security needs. 

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

Re: 9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

> On Jun 1, 2019, at 4:22 PM, Steve Malikoff via cctalk  
> wrote:
> 
> BTW If the old rubber rings one the hubs are too
> expanded and won't allow a tape reel to slide on, just replace with a # BS336 
> O-ring
> from a bearings/seals/gasket shop. These are cheap, readily available and 
> takes seconds
> to install for a perfect fit.

Thanks! That's bound to be helpful advice... if not now, then someday in the 
future.

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

Re: 9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

> On Jun 1, 2019, at 15:27, John H. Reinhardt via cctalk 
>  wrote:
> 
> Congrats!!  Should be fun to play with.  I just picked up a Micro PDP-11/53 
> which is about the biggest I can fit into my office/computer room.  lol
> 

Neat! I’d like to get a PDP-11 in that form factor someday. 

Re: 9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

> On Jun 1, 2019, at 14:57, John H. Reinhardt via cctalk 
>  wrote:
> Is this the system that was on Reddit?

Yes. I’ll be fetching it next weekend. I’m excited! I wonder if the hard drive 
is still usable, and if there is anything interesting on it?

By a chance meeting with my neighbor today, I learned he has a bunch of pallet 
racking from a defunct business he emptied out. He offered that I could go grab 
some for myself. He also mentioned that he planned to bring some to his farm 
next door to me before he sells off the rest. Since I’m planning to rent a 
truck next weekend anyway, I offered to help out by hauling for both of us in 
exchange for taking a skim off the top of the pile. It’ll be a busy weekend!

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

Re: 9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

Cool. So that means that this 11/34A has more backplane slots than the base 
model? The programmer panel is also appealing. I presume that the Kennedy 9000 
doesn’t have a Pertec interface, then?

It remains to be seen whether I ever start my 11/44 restoration vs. moving it 
along to another collector and using some of the boards I accumulated for it in 
the 11/34A. I’m on the fence about that. 

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

Re: 9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

Thanks!

I am taking the whole system. It's in a rack with a PDP-11/34A, a System 
Industries 9400 controller, and what looks to me like a Fujitsu M228x series 
hard drive:

https://pbs.twimg.com/media/D77fRMFU0AEQtSO.jpg

I grabbed the M228x manuals from Bitsavers to look up how the spindle and 
positioner locks work. I had been planning to de-rack it all so my dad and I 
could load it into my pickup truck in bite-sized pieces, but I think I would be 
better off renting a box truck with a lift gate.

What are the chances that it's the same PDP-11/34A that Warner did backups on? 
:D

Would the brown panel between the tape drive and computer be a filler panel, or 
part of the 11/34A? I don't know anything about the system configuration yet 
other than what can be seen in that picture.

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

9-Track Magtape Drive ID

[Mark J. Blair via cctalk]

Does anybody here recognize the make and model of this tape drive?

https://pbs.twimg.com/media/D7_mfdfUIAMcTly.jpg

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

Re: Newbie Punch Tape Questions

[Mark J. Blair via cctalk]

> On Dec 24, 2018, at 11:33 AM, Columbia Valley Maker Space via cctalk 
>  wrote:
> 
> The Mylar reel would have been the programming for a CNC machine. I
> suspect the first part of the reel may be some boot loader or init
> routine. 

I could definitely be mistaken, but my first guess would be that a tape with 
CNC machine programming would contain G code, and look like cryptic ASCII text. 
I'm interested in hearing what you find.

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

Re: VAX 9440

[Mark J. Blair via cctalk]

What a majestic system! When I saw the teaser picture of the backs of racks on 
Twitter, I was assuming something in the 11/78x series. I don't know anything 
about the 9440 yet, so it'll be fun to read up on that.

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

Re: desoldering (was Re: VAX 9440)

[Mark J. Blair via cctalk]

On the topic of desoldering tweezers: I don't like them. I've done tons of 
rework of components down to 0201 size. I consider 0201 to be difficult, but I 
found that once I could work on 0201 components at all, 0402 suddenly seemed 
easy to work with!

Anyway, the tweezers I've used had poor tip alignment, tips too blunt for small 
components, and of course the whole handle has to be positioned in a plane such 
that both tips touch their corresponding terminals at the same time. And that 
was with high-end Metcal tweezers.

Instead, I use two pencil-type irons, one in each hand, working under a stereo 
microscope. The tips are much better, and manipulating each tip independently 
provides great control of what's going on. Only drawback is that if you want to 
use a fancy, expensive iron, now you get to buy two of them. If you're tempted 
by a soldering station with two or more outputs, make sure that it can drive 
both simultaneously. There are dual-output stations that have two outputs but 
can only run one at a time, as well as ones which can drive two irons at once.

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

Re: Advice requested on proper disposal of Seagate ST3000DM001 disk drives

[Mark J. Blair via cctalk]

How about removing the (presumably aluminum) platters, case castings, and any 
other aluminum parts, grinding it all down to fine aluminum flakes, making 
thermite out of that, then using it to slag the rest of the non-aluminum parts?

Then shoot the slag pile with a .50 BMG.

Then drop that into lava.

Then scoop out the contaminated lava and drop it into a singularity.

Becase overkill is best kind of kill.

Did I miss any steps?

Oh, yeah: Play country music the whole time, to make it all more painful for 
the drives.

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

Re: Fall cleaning - 9-track drives available

[Mark J. Blair via cctalk]

> On Sep 21, 2018, at 7:44 PM, Bob Rosenbloom via cctalk 
>  wrote:
> 
> 
> All are located in Santa Cruz, CA and need to be gone soon, I need the room 
> in my hangar. Come get them!
> 
> Photos here: http://dvq.com/fall_cleaning/

If I'm not mistaken, that CDC drive uses the same mechanism as my DEC TU81. My 
workshop is the exact same style of steel arch building as your hangar, but 
mine is a lot more full of junk than your hangar is! :D

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

Re: Fall cleaning - 9-track drives available

[Mark J. Blair via cctalk]

I'm sure relieved that you didn't say "DEC TU77 drive" and "near Riverside, 
CA", because I lack spare cash, empty floor space, and impulse control! :)


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

Re: Oddball Terminals (Was: Re: VT100's)

[Mark J. Blair via cctalk]

That’s it! The terminal I had was definitely the one in this picture:

http://bitsavers.org/pdf/dec/terminal/vt02/vt02_1.jpg

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

Re: Oddball Terminals (Was: Re: VT100's)

[Mark J. Blair via cctalk]

Thanks for digging that up! I had never managed to google up any details 
before. 

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

Re: Oddball Terminals (Was: Re: VT100's)

[Mark J. Blair via cctalk]

> On Sep 7, 2018, at 8:41 AM, Bob Rosenbloom via cctalk  
> wrote:
> 
> The display was most likely a Tektronix 611. DEC used them with their point 
> plot display systems like the VC8E.

I am pretty sure that the display was a 611 in its vertical configuration:

http://w140.com/tekwiki/wiki/611

The display was a fully enclosed standalone unit, not a bare chassis. It sat on 
top of the bottom chassis of the terminal and then had another cover fitted 
over it.

It had screen burn which indicated its use as part of a text terminal, but I 
don't know if the character generation was originally performed in the bottom 
chassis or by external equipment. The small DEC wire wrap backplane in the 
bottom chassis didn't seem big enough to implement all of that with flip chips. 
Maybe the backplane was just used for keyboard interface, and character 
generation was done by equipment external to the terminal?

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

Oddball Terminals (Was: Re: VT100's)

[Mark J. Blair via cctalk]

A long time ago, I had the incomplete remnants of an oddball terminal which I 
retrieved from a junk pile at a small, obscure school in Pasadena. I'll try to 
describe it as best I can, based on old memory. I could have sworn that it had 
a dataplate label identifying it as a DEC VT02, but that could be way off the 
mark.

It was built around a Tektronix vector storage display, oriented in portrait 
mode. It had quite a bit of screen burn from its long life displaying text. I 
don't recall the model number of the display, but I might recognize one if I 
saw it. It was quite long, making the whole terminal quite long. It had X, Y 
and Z BNC inputs, and it had a neat test mode that drew a spiral on the screen.

The display sat on top of a long chassis with a keyboard at one end, a small 
Flip Chip backplane around the middle, and a power supply (probably linear, 
IIRC) at the rear end. I don't think that the Flip Chip boards were still in it 
when I got it, but it came along with a small box of spare Flip Chips.

After setting the big Tektronix display on top of the lower chassis, there was 
a long U-shaped sheet metal cover that sat over the top and covered the 
display, making it look somewhat like a single device rather than a stack of 
two things. The lower chassis and the top cover were painted approximately 
white as I recall.

I never did anything interesting with the display other than occasionally 
driving it with signal generators, and I got rid of the whole pile a long, long 
time ago.

Does that old beast sound remotely familiar to anybody here? How hard should I 
kick myself for not keeping it?

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

Re: Pdp 11/34 System for sale in Riverside,ca

[Mark J. Blair via cctalk]

> On Aug 1, 2018, at 8:32 AM, Wayne S via cctalk  wrote:
> 
> http://www.ctonlineauctions.com/detail.asp?id=746466
> 
> From the pictures it looks to be a fairly complete system with Kennedy tape 
> drive.
> Has a System industries controller but doesn't appear to have a disk drive.

Looks like somebody got a good deal, with a closing price of $32. I hope the 
pickup goes smoothly this weekend.


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

Re: Pdp 11/34 System for sale in Riverside,ca

[Mark J. Blair via cctalk]

Ok, I've studied the pictures carefully and given it some deep consideration, 
and I've decided that I do not want it. I hope that somebody adopts it!

Judging by the power tools that are also listed in the same event, I'd say that 
the person whose estate this is from was definitely One Of Us.

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

Re: Pdp 11/34 System for sale in Riverside,ca

[Mark J. Blair via cctalk]

It looks lovely, and I live just outside the Riverside city limits. I'm awfully 
short on both money and indoor storage space right now, though. :(

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

Re: Thicknet/10base5 Test Segment: The Cable is In!

[Mark J. Blair via cctalk]

> On Jun 25, 2018, at 2:20 PM, systems_glitch via cctalk 
>  wrote:
> I do have a very
> few NOS Cabletron ST-500-01 transceiver/non-intrusive tap kits as well.


What does non-intrusive mean in this context? I thought that thick ethernet 
taps always required drilling a hole in the cable.


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

Re: CDC 6600 display character generation

[Mark J. Blair via cctalk]

> On Jun 6, 2018, at 11:50 PM, Rick Bensene via cctalk  
> wrote:
> 
> Believe me, the console did spit out a lot of sparks and little blobs of
> molten metal, along with quite a bit of smoke.  I still have a small
> scar on my left leg where one of the little blobs of metal burned me
> after burning through the material of my slacks.

This reminds me of every TV show and movie I've seen where consoles begin 
exploding on a space ship during a battle. All of this time, I thought that was 
entirely a Hollywood fabrication!


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

Re: Modifying microcode

[Mark J. Blair via cctalk]

> On Jun 3, 2018, at 7:37 PM, Ethan Dicks via cctalk  
> wrote:
> 
> We used to purchase 11/725s for parts to keep our 11/730 running.
> Much cheaper because "nobody" wanted an 11/725 in the early 90s (I
> still have one.  I wish I could afford a Unibus controller to replace
> the KLESI/U and RC25).

Back around the early 1990s, a friend of mine had an 11/725 and an 11/730 in 
his apartment. One of then had a bad PROM chip, so he could only run one at a 
time.

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

Re: I ran across this strange modernistic? Data General ...odd?

[Mark J. Blair via cctalk]

> On May 26, 2018, at 9:38 AM, Bruce Ray via cctalk  
> wrote:
> 
> And 'yes', Novas and its derivatives are still used today...


That's news to me, and it sounds quite interesting. Would you mind elaborating 
on that?

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

Re: (OT) Re: Is This A Shill?

[Mark J. Blair via cctalk]

On May 2, 2018, at 09:08, Chuck Guzis via cctalk  wrote:
> 
> Although eBay in the past has tried to kill off sniping because it
> reduces the number of visits an individual might pay to their site, I
> think they've given up with trying to kill the sniping system.

If eBay really wanted to kill sniping and maximize winning bids, I think they 
could simply change the format from fixed ending time to automatically 
extending the auction period N minutes past the last bid. There would still be 
some benefit to a bidder for bidding late and hoping nobody notices, but there 
would always be a window of up to N minutes for other bidders to decide to 
increase their losing bid. It would end up as a a hybrid of proxy bid + live 
auction.

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

Re: TRS-80 Fragmentation

[Mark J. Blair via cctalk]

> On Apr 26, 2018, at 14:25, Geoffrey Oltmans via cctalk 
>  wrote:
> 
> TRS-80 Model II and 16, 68k based "business" machines

The Models II and 12 were Z80 based machines. The models 16 and 6000 were the 
same Z80 based machines with 68k subsystems added via additional cards to allow 
them to run Xenix.

Re: Rick Dickinson, ZX Spectrum designer, RIP

[Mark J. Blair via cctalk]

Over here in the US, I remember seeing the Sinclair QL in a magazine (probably 
Byte?) and thinking it looked exotic and interesting. I thought the little tape 
drives looked neat, and didn’t know enough to appreciate how much better a 
floppy drive would have made the system.

I have no regrets at all about getting an Amiga 1000 to take to college, and 
now I appreciate even better than then just how lucky I was. But to this day, 
I’d still like to play with a QL and get an idea of what it would have been 
like to head off to college with a shiny new one of those. There are a few 
other UK computers which I’m also curious about, since they’re not so common 
over here in the US. 

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

Re: new disassembler vs IDA (was Re: 8085 Dissasembly?)

[Mark J. Blair via cctalk]

> On Apr 19, 2018, at 9:19 AM, Eric Smith via cctalk  
> wrote:
> 
> For the 1802, I've used a really crude disassembler written in C. The 1802
> instruction set isn't very complicated, so a disassembler for it isn't
> either.  It's been so many years since I actually disassembled 1802 code
> that I'm not sure I still have the disassembler around.

Well, you're welcome to use dismantler on CDP1802 code! :)


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

Re: 8085 Dissasembly?

[Mark J. Blair via cctalk]

> On Apr 18, 2018, at 2:50 AM, Torfinn Ingolfsen via cctech 
>  wrote:
> 
> Since it has not been mentioned yet: NF6X's dismantler supports the
> 8085 (and a couple of other CPUs): https://github.com/NF6X/dismantler
> It is written in Python, so it should run on any platform where Python
> is available. From the description "semiautomatic code recognition"
> and "allows binary files to be disassembled from the command line".

My main motivation for writing dismantler was that I was intrigued by 
recursive-descent disassemblers such as IDA (which I had seen in use in videos, 
blog posts and presentations), but didn't want to pay for IDA at the time. I've 
recently purchased IDA Starter, so I may not use my own disassembler any more 
for future reverse engineering projects. Dismantler is a pale shadow of IDA, 
but it's still a big improvement over the simple disassemblers I've used in 
previous reverse engineering projects.

Some of the future reverse engineering projects I have on my to-do list involve 
the CDP1802 processor, which IDA presently doesn't support. When I get to them 
I'll have to decide whether to use dismantler vs. learning how to add CDP1802 
support to IDA. I'm leaning towards the latter, because IDA is so much fancier 
than dismantler is.

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

Software for AN/UGC-144 Communications Terminal?

[Mark J. Blair via cctalk]

I posted this originally on the ArmyRadios mailing list, but I think it's just 
computery enough that it may be of interest here, too. And maybe somebody here 
even has the answers to my questions!

I just got an AN/UGC-144 communications terminal. It looks unused, and it came 
with cables and  manuals (-12 and -30, but not including schematic diagrams or 
component-level details). It powers up, but fails to boot from its internal 
hard drive. The screen has some bad rows and columns, and the gas spring that 
supports the display needs to be replaced. I shared a bunch of pictures on 
Twitter today as I unpacked it and started playing with it, in this thread:

https://twitter.com/nf6x/status/980174491673178112

Here are direct links to some of the more interesting pictures in that long 
thread:

https://twitter.com/nf6x/status/980198067767947264
https://twitter.com/nf6x/status/980202029766230016
https://twitter.com/nf6x/status/980263764325941249
https://twitter.com/nf6x/status/980302909165338624

I haven't found very much about the terminal online yet, and I expect that I 
have a long road ahead of me as I try to fix the display and see if anything 
can be recovered from the hard drive. If the original software isn't present on 
the hard drive and recoverable, then this may be a great big doorstop! But it 
may also be a fun reverse-engineering project. I haven't dug into it deeply 
enough yet to determine whether it's built around an embedded PC-clone 
architecture or is something completely custom. In any case, I'll naturally 
want to try to dump and disassemble any ROMs I find inside of it. The CAGE code 
is for Sypris Electronics, and the boot screen shows a Honeywell copyright 
notice. I found that it tried to access a blank floppy diskette at boot time in 
the right drive, but I didn't have an MS-DOS boot diskette handy at the moment 
to see if it could boot from it. I'll give that a try when I have a chance... 
but probably after Easter.

Have any software diskettes, programs, disk images, etc. for this terminal made 
it out into the wild? I presume that there were boot and installation diskettes 
that were used for hard drive formatting and software installation, and I would 
really love to get my hands on anything like that... especially if it turns out 
the the hard drive in my terminal is blank and/or dead. I'll be satisfied if I 
can use this rig as a dumb terminal for RTTY use, and even happier if I can do 
anything fancier with it.

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

Re: Identifying vacuum tube module

[Mark J. Blair via cctalk]

> On Mar 25, 2018, at 12:34, Kyle Owen via cctalk  wrote:
> 
> Anyone knows what these go to?
> 
> https://imgur.com/a/CpxLs 

If the 5815 is a Federal Supply Classification, then the module would most 
likely be used in some sort of teletype or facsimile equipment.

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

Re: IBM 6094-010 "Dials" protocol?

[Mark J. Blair via cctalk]

> On Mar 24, 2018, at 22:29, Michael Brutman via cctalk  
> wrote:
> 
> Picture here: https://i.imgur.com/ClCw070.jpg 
> 

Neat! I haven't seen one of those since 1987, when I briefly played with a 
workstation that had one of those in an unguarded computer room in college. It 
was running some sort of CAD demo in which you could rotate, translate, and 
scale a wireframe model with the dials. I seem to recall that it was propped up 
diagonally on some sort of stand, but I don't remember if that was a standard 
feature vs. something cobbled together locally.

Good luck learning how to talk to it. I can think of a number of different 
applications in which a physical interface like that might be nice.

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

Re: WTB Intel 7110 Bubble Memory Subsystem or Chipset

[Mark J. Blair via cctalk]

> On Feb 23, 2018, at 07:11, Anders Nelson  wrote:
> 
> That's one of the most beautiful machines I've ever seen! Are they 
> rare/expensive? (I'm guessing yes)

Yes to both! I don't know how many are out in the wild today, and I don't know 
how many were made. I don't even know yet whether they were truly fielded, or 
if they failed to be selected to fill the role that they were presumably 
competing for.



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

Re: WTB Intel 7110 Bubble Memory Subsystem or Chipset

[Mark J. Blair via cctalk]

> On Feb 22, 2018, at 2:33 PM, Eric Smith via cctalk  
> wrote:
> 
> If you do lose the formatting of an Intel 7110 bubble memory device, to
> reformat it you need something Intel called a "seed module". The
> instructions to build a seed module are in the BPK72 manual.


I've seen those instructions. As I understand it, I may need to do that to 
restore a module to operation if it's lost its seed. But if that has happened 
to either of the two modules in my firmware cartridge already, then it's all 
over.

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

Re: A couple of RL02 questions

[Mark J. Blair via cctalk]

> On Jan 28, 2018, at 20:56, Marc Howard via cctalk  
> wrote:
> 
> I've got two RL02 units.  One is a parts unit and has an access plate for
> the door solenoid.  I can open it.  The other has no access plate nor is
> there a cutout for one.  How do I open this cover with the power off?  This
> is a newer unit as it has head lock screws on the bottom of the drive.

All of my RL02 drives are the ones without the solenoid access covers. They're 
still easy to open without power. Loosen the four screws holding down the rear 
portion of the plastic top cover. Lift it up a bit where it and the door are 
hinged together, and then you should be able to unlatch the door. You should 
only need to lift it a quarter inch or so to let the door latch clear the 
interlock solenoid pin.

If I recall correctly, the screws on the bottom are to keep the spindle motor 
from bouncing around. The heads are locked in place by a little metal plate in 
the disk cartridge compartment, which blocks them from sliding out of the 
parked position. Loosen the single screw holding the plate in place, then 
rotate it 90 degrees to cover or uncover the ends of the heads.


> The second question has to do with rack mounting.  I want to mount this in
> a H960 cabinet but will obviously need to slide it out to replace packs.
> All the unit has is a thin rail on both sides that is riveted to the unit.
> It looks like chassis slides were there originally.  Does anyone have
> either the DEC part # for the slides or a contemporary part # for one that
> will work?

There are rails which bolt into the rack, and then the drive sits on top of the 
rails using those sheet metal brackets riveted onto the sides of the drive. I 
don't have any spares; I don't even have enough for all of my drives. I may be 
able to dig up the part numbers if somebody else doesn't pipe up first. They're 
listed in the maintenance prints. I am not aware of any generic modern rails 
which work at this time.

In my VAX-11/730, the RL02 is installed at the very top of the short rack 
(which doesn't have a top cover), so it is accessible without sliding it out of 
the rack. It still has the slides, but it's normally strapped in place by a 
shipping hook at the back of the rack. I've thought about making a top which 
rests on the side panels of the rack and removing the shipping hook, so I can 
set stuff (such as a terminal?) on top of the system and then slide out the 
drive to change packs.

Good luck!


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

Re: ultrasonic cleaning for disk heads

[Mark J. Blair via cctalk]

Speaking of these drives, I have a single decpack cartridge which hitchhiked 
along with a purchase of RL02 packs. It's marked "decpack 2200 BPI-12" and has 
12 sector notches in the hub. Does that mean that it was most likely used with 
an RK05 drive in a PDP-11 system? I seem to recall that packs used with a PDP-8 
system would have 16 sector notches. I hope that I can procure a matching drive 
for it one of these days, even though Marc's video makes me think I'd be 
royally screwed if I didn't also manage to procure a good alignment pack to go 
with it, and maybe some spare heads. I don't have any experience with the 
front-loading drives yet.

Labels on the pack indicate that it saw some DEC maintenance on 1/6/84, and it 
was used by somebody named Fred Knight. It's labeled "KMC-LP Testing Pack". I 
know it's a long shot, but it would be neat if any of that meant something to 
anybody on the list.

I don't know anything about how to clean hard drive packs, and that's something 
I'd like to learn about.

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

Re:

[Mark J. Blair via cctalk]

> On Jan 27, 2018, at 10:23, Adrian Stoness via cctech  
> wrote:
> 
> ipa as in beer?

Isopropyl alcohol. Not very good for drinking; even store-brand vodka in 
plastic jugs is less harsh. :)


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

Re: ultrasonic cleaning for disk heads

[Mark J. Blair via cctalk]

I thoroughly enjoyed Marc's video of the head cleaning.

Some dumb questions from a guy who has not yet experienced his first head crash 
on a removable-pack hard drive:

When it happens, am I correct in assuming that the pack is toast, and should 
never be loaded again?

My removable-pack drives are DEC RL02 drives and a Data General drive with one 
removable and one fixed platter, using cartridges of the same style as the 
RL02. The DG drive has a glass encoder, so I presume that it requires 
realignment after removing the heads for cleaning. I might have acquired an 
alignment pack for it already. But since the RL02 drives use servo bursts on 
the media, do they require realignment after removing and replacing the heads?

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

Re: A walk through of my legendary warehouse sale in the 1990s.

[Mark J. Blair via cctalk]

> On Jan 20, 2018, at 18:26, Paxton Hoag via cctalk  
> wrote:
> 
> This is a digitized HI8 tape of a walk through of an early Warehouse Sale I
> ran from 1995 to 1998. There is a small sections of collectable computers
> in the middle of the tape with a few others scattered through the sale.
> Fond memories and hard to believe it was 22 years ago.

I see some DEC gear that I covet at 3:48. Now where did I leave my time machine?

https://youtu.be/8Pme8mZU-Xc?t=3m48s 

More retro computer gear begins showing up at 8:36:

https://youtu.be/8Pme8mZU-Xc?t=8m36s 

I think I see some Color Computers at 12:17.

https://youtu.be/8Pme8mZU-Xc?t=12m17s 

Heaps of DEC toys at 19:15!

https://youtu.be/8Pme8mZU-Xc?t=19m15s 

Re: DECtape madness

[Mark J. Blair via cctalk]

> On Jan 13, 2018, at 08:52, Bill Gunshannon via cctalk  
> wrote:
> 
> So, where were all these people when I was trying to clean out
> my old house a couple years ago?  I threw out piles of tapes of
> various formats because I couldn't find anyone to take them for
> postage.

I'm sorry that I missed that event, Bill! I'd be happy to add a DECtape drive 
and a handful of usable DECtapes to my PDP-8/M project, but I don't want that 
dearly enough to pay the going eBay prices for that kind of gear at this time. 
Not that I can really complain, as I'm fortunate to have lots of other cool 
stuff running the range from free gifts to expensive purchases; I just haven't 
been at the right node of place + time + checking account balance to have 
acquired DECtape family gear yet, and I was born just a bit too late to have 
experienced it in college or the workplace.

I sure wish that I would have anticipated that I'd become interested in 
retrocomputing in the 201x decade, so I wouldn't have gotten rid of a few 
specific items over the years that I now wish I still had, and I could have 
kept my eyes open for other items that I might have acquired cheap or free at 
the moment that interest in them was at a minimum.

Naturally, there's plenty of stuff in recent years that I have considered to be 
uninteresting junk to be discarded. I wonder if I'll regret having junked it in 
another decade or three, or if my sense of nostalgia will remain rooted to my 
younger years and earlier?

Re: QSIC update and request

[Mark J. Blair via cctalk]

This looks pretty interesting! I think I've managed to miss previous discussion 
of it. I wonder if it might also be useful in any of the QBUS MicroVAXen?

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

Re: Attaching SIMH devices without halting simulation?

[Mark J. Blair via cctalk]

> On Dec 31, 2017, at 5:07 PM, J. David Bryan via cctalk 
>  wrote:
> 
> 
> You mentioned that you "tried putting the system console on a telnet port," 
> so you might have used the "SET CONSOLE TELNET" command (section 3.14 in 
> the user's guide).

Ah, yes, I think that's what I did.

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

Re: Attaching SIMH devices without halting simulation?

[Mark J. Blair via cctalk]

> On Dec 31, 2017, at 14:10, william degnan  wrote:
> 
> I thought you set all devices you planned to use "online" so you could mount 
> them later?  I don't simh vax much so thanks for the correction as to the 
> procedure.  I mostly do pdp8 or pdp11 stuff, or esoteric hardware.
> 
> 

That's what I'd generally do for things like fixed disks. But in normal use of, 
say, a VAX running VMS, you'll want to be able to change tapes without 
rebooting the whole system in order to restart SIMH with a different 
configuration file. Even on a simulated PDP-11 running RT-11, you might want to 
swap out simulated floppies in one of the RX02 drives, for example.

Pausing a simulated PDP-11 running RT-11 momentarily to attach a different 
image isn't a big deal, because the system was probably sitting idle, anyway. 
But halting a VAX that's serving as a DECnet area router or a cluster disk 
server just to swap a tape or disk pack is not ideal.

Anyway, the remote console feature appears to do exactly what I want. Yay!

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

Re: Attaching SIMH devices without halting simulation?

[Mark J. Blair via cctalk]

> On Dec 31, 2017, at 13:52, J. David Bryan  wrote:
> 
> See section 3.15, "Remote Console" in the SIMH User's Guide.  The "SET 
> REMOTE TELNET" command will allow you to attach and detach while the 
> simulator is running.

That appears to work perfectly. I don't know what I did wrong when I tried that 
before. Thanks!


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

Re: Attaching SIMH devices without halting simulation?

[Mark J. Blair via cctalk]

> On Dec 31, 2017, at 13:47, william degnan  wrote:
> 
> Yes, but you were not able to attach in your startup script?  That's when to 
> do it.
> 


It's common practice, and frequently a necessity, to mount media such as tapes 
without rebooting the machine they're being mounted on.


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

Attaching SIMH devices without halting simulation?

[Mark J. Blair via cctalk]

I've been experimenting with the SIMH VAX simulators a lot lately. The only way 
I know of to mount a tape, disk pack, CD-ROM, etc. after boot time is to halt 
the simulation with ^e to get to the SIMH command prompt, ATTACH the desired 
image, and then resume the simulation with CONTINUE.

Is there any way to attach/detach media images in SIMH without halting the 
simulation? I've tried putting the system console on a telnet port so it 
doesn't occupy SIMH's controlling terminal, and I found that it's still 
necessary to halt the simulation to get back to the SIMH command prompt.

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

Re: Dec-10 Day announcement from Living Computers: Museum + Labs

[Mark J. Blair via cctalk]

> On Dec 10, 2017, at 00:21, Rich Alderson via cctalk  
> wrote:
> 
> Happy DEC-10 Day!
> 
> It is my honor to announce that we at Living Computers: Museum + Labs
> are releasing to the computing community our Massbus Disk Emulator
> and all the associated software.

This is wonderful! And the timing of your announcement makes me giggle with 
delight. I don't have any Massbus equipment, but I still love this on general 
principle.

> We expect that it will also work with the RH780 on the VAX-11/780 and
> VAX-11/785 although we have not yet tested it in this configuration.

If somebody would like to sell me a Massbus-equipped 780 or 785 system, I can 
test that out for y'all. :)


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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 8:27 PM, Curious Marc  wrote:
> 
>> I think that the upgraded B model ROMs in the PRM-85 are supposed to let it 
>> use the newer drives. 
> Yes it does. I have an HP 85A, the PRM 85 and a 9122, and that combo works 
> beautifully. I am not sure I ever tried it with high density diskettes 
> though. I could check that if you want.


Thanks for confirming that, Marc. I just picked up my PRM-85 board today, and 
it looks like I should be able to purchase a couple of different models of HPIB 
3.5" floppy drives from other collectors soonish.

Has anybody gotten around to sharing CAD models for a 3D-printable PRM-85 case 
yet, or shall I get to work on that task?

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

Re: "Personal" Computers (Was: Details about IBM's early 'scientific' computers)

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 5:09 PM, Paul Koning via cctalk  
> wrote:
> 
> 
> Earlier, there was the SAGE computer (the air defense one, not the PC by the 
> same name), which had built-in ash trays at each operator station.

With all of the possibly apocryphal stories of computer users mistaking CD 
drive trays for coffee cup holders, I can't help but wonder if anybody has ever 
mistaken the metallic cartridge slot cavity of the Atari 400/800 for an ash 
tray with a flip-up lid.

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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 4:45 PM, Eric Schlaepfer  wrote:
> 
> It'd be interesting to find out how well that PRM-85 works. I've laid out a 
> board for a rough equivalent but I haven't fabbed it out. It may be cheaper 
> for me to buy that instead.
> 
> I've also got a 9122C but I don't have the mass storage ROM so I can't use it 
> with my 85. Right now I'm using it with my 9000 series 300.


I've just received my PRM-85, and it looks like I have leads on a couple of 
different floppy drives now. I'll be happy to share my experiences.


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

Re: Drive capacity names (Was: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 09:44, Fred Cisin via cctalk  
> wrote:
> 
>>> No, the 9122C model has two 1.44M drives. HP made several earlier 3.5"
> On Wed, 15 Nov 2017, Christian Corti via cctalk wrote:
>> No, the 9122C has two high-density, two-sided 80 cylinder drives. A drive 
>> has no capacity, this is the function of the on-disk format.
>> ;-)
> 
> "high-density" is even more meaningless than referring to them by their 
> capacity in a given format.  It is a BOGUS marketing term!


Bogus as it may be, compatible media for those drives commonly has "HD" printed 
on the box and molded into the diskette's plastic jacket. It's a useful term 
for identifying the compatible media.

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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 09:33, Paul Berger via cctalk  
> wrote:
> 
> 720K media is pretty easy to get as well, I bought 100 "used" disks from 
> floppydisk.com, and it is hard to tell they have ever been used and I have 
> not had any problems with them.  I also bought a lot on eBay that where 
> previously used on an Amiga that majority of them where OK and the where a 
> mix of single and double sided media.

That's good to know. I'll check them out. That should open up my options, as 
well as giving me a way to get more media for machines like my Amigas and early 
Macs.


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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 15, 2017, at 01:31, Christian Corti via cctalk  
> wrote:
> 
> No, the 9122C has two high-density, two-sided 80 cylinder drives. A drive has 
> no capacity, this is the function of the on-disk format.
> ;-)

Ah! That's technically correct, which is, of course, the best kind of correct.

Well, if we're being pedantic, then we might also refer to the drives by their 
unformatted capacity, as HP themselves sometimes did:

https://pbs.twimg.com/media/DOr81HpVQAAn-X5.jpg

That makes them 2-Mbyte drives. ;-)

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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 10:57 PM, Ed Sharpe via cctalk  
> wrote:
> 
> you have me real curious,as to what is in that padded hp case..


What are you referring to?


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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 20:44, Ed Sharpe via cctalk  wrote:
> 
> remember too.. there were hpib 8 inch and 5 inch drives wish I had saved 
> some!!!

Those would certainly interest me if I happen upon any at a price that I like. 
Same goes for an HPIB 9 track tape drive. But since the HP Series 80 stuff lies 
more towards the fringes of my interests at this time, I have a hunch that I am 
not too likely to find one of those at a price I would like to pay any time 
soon. Naturally, I’m more prone to pay real money for things closer to my core 
interests. But if I do happen upon any of that sort of gear at the right time, 
place, and price, then that will be really cool. Sometimes I surprise myself. I 
never expected to be interested in the DG Nova until I stumbled over a chance 
to buy one along with a PDP-11/03 system that interested me more at the time. 
Now I am glad that I have that cool Nova system, even though I still haven’t 
managed to get it talking to its hard drive. 

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 20:33, Ed Sharpe via cctalk  wrote:
> 
> ok back in my day.. I do not think 85 adressed modern drive of 1.44 meg..? so 
> that was what I was going on.. yes if you can use 1.44 do so.. older new 
> media hard to find... 

I am still new to this HP-85 stuff, but I think you are correct about the A 
model system not originally handling the 1.44M drive. I think that the upgraded 
B model ROMs in the PRM-85 are supposed to let it use the newer drives. 

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 20:11, Ed Sharpe via cctalk  wrote:
> 
> wondervifcthec9122 drives,will work on 85?
> 

I think I can guess what you meant to say there... :)

I’ve ordered a PRM-85 (a modern reprogrammable ROM drawer replacement) which 
includes the HP-85B version of the Mass Storage ROM, and the Extended Mass 
Storage ROM. Based on what I have read, I think that should let my A model use 
the newer 9122C drive, and other drives using either the Amigo or SS-80 
protocols.

I’d like to get the 9122C mostly because I have a much easier time finding 
1.44M media than the older double density media. eBay and I don’t talk, so that 
limits my options a bit. If I had easy access to lots of 3.5” DD media, then I 
would consider getting one of the more plentiful (?) other 3.5” HPIB floppy 
drives. 

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 7:24 PM, Ed Sharpe via cctalk  
> wrote:
> 
> try 9121 drives!!!. ed!

No, thanks. I'd like a 9122C drive.


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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 6:35 PM, Paul Berger via cctalk  
> wrote:
> 
> Well I do have a surplus 9122C however only one drive works and I am on the 
> other side of the continent.

Hmm, I'll consider yours if a more workinger one doesn't appear. That 
locational thing can be solved if you're willing to pack and ship. Do you have 
any idea what might be wrong with the second drive?


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

Re: WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

> On Nov 14, 2017, at 5:24 PM, william degnan  wrote:
> 
> Those drives are 720 each 3.5".

No, the 9122C model has two 1.44M drives. HP made several earlier 3.5" drive 
units with either 360k or 720k drive capacities.

I don't have a compatible IEEE-488 card for use with the HPDrive software. I'm 
curious about the open source hp85disk project, and might build hardware to 
work with it sometime. In any case, I'm interested in getting a 9122C drive.


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

WTB: HP-85 16k RAM Module and HPIB Floppy Drive

[Mark J. Blair via cctalk]

I just got my HP-85 working for the first time over the weekend (except for its 
tape drive, which is still a work in progress). I'd like to acquire some 
accessories for it:

1) HP 82903A 16k RAM module

2) HP 9122C dual 1.44M 3.2" floppy diskette drive

Do any of y'all have either of those items available for swap or sale? I'm 
located in southern California.

Those two items are at the top of my HP-85 want list, but I might also be 
interested in other related bits such as the 82940A GPIO Interface, other 
compatible HPIB mass storage, etc.

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

Re: RL02 Spinup fails

[Mark J. Blair via cctalk]

> On Nov 6, 2017, at 10:21, Aaron Jackson via cctalk  
> wrote:
> 
> I based my terminator off Mark
> Blair's RL02 to USB project:
> 
> https://github.com/NF6X/RL02-USB/blob/master/pcbs/RL02-USB-terminator/RL02-USB-terminator.pdf

Hi there! Just one warning: My project stalled after I ordered boards and lost 
inertia while waiting for them, and I have not yet put together the hardware. 
Thus, I can’t guarantee that my terminator design is correct yet. I’m glad that 
it has been deemed to be potentially useful even in its unfinished state, and I 
sure hope that I haven’t led anybody down the wrong path due to any errors that 
may be in the design. Good luck!

Re: Wanted: small composite CRT monitor

[Mark J. Blair via cctalk]

I suggest that you keep your eyes open for a small CRT-based CCTV monitor. 
Possible sources include eBay, Craigslist, Goodwill, etc., as well as folks on 
lists like this one.

I've been looking for an old Sanyo VM-4209 or VM-4509 monochrome monitor for a 
while, to put on my SOL-20. One of those would be Just Right for the SOL-20, as 
well as for an early Apple II series machine. The few I've seen have been in 
poor shape, yet listed for RARE L@@K STEVE JOBS prices. I recently found a 
younger monitor via Goodwill. It's about a decade too new to be Just Right for 
my SOL-20, but it at least has similar boxy styling to the monitor I'd really 
like. Newer monitors like that are a lot less rare, and still tend to have more 
reasonable prices. Something like that might suit your needs well.

Now, you say you want a color monitor. I think that similar color CCTV monitors 
are even more commonly available. I haven't been paying close attention to them 
since I've been looking for a specific monochrome monitor, but I think I've 
seen various color ones bouncing off my brain's spam filters. I think that one 
of the small, boxy, color CRT CCTV monitors might look quite nice with your IIc.

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

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

[Mark J. Blair via cctalk]

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


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

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

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

Re: Convex documentation online (C220 arrived)

[Mark J. Blair via cctalk]

> On Aug 7, 2017, at 12:13 AM, Camiel Vanderhoeven 
>  wrote:
> 
> That would have been the CPU cabinet for the C240 (which is twice as wide
> as the C220¹s CPU cabinet. The C240¹s CPU consumes - i.e. converts to heat
> - about 20 kilowatts of power, so that would indeed have created a hotspot
> in a computer room. It will surely create a hotspot in my barn!


Ok, that makes sense. All I remember is that from the rear side of the cabinet, 
it was behind the exhaust vents at the lower right corner that was the optimal 
place in the computer room to curl up in a fetal position at 6AM, when the main 
building A/C came on and the computer room temperature plummeted, right about 
when the metabolism of an exhausted college student working a graveyard 
computer operator shift was at minimum. But it was all worth it for a key to 
the computer room, and unlimited root access on Sun workstations when most 
students were lucky to get a small quota on the heavily-loaded Sequent Symmetry 
series machine. Oh, and they paid me, too. :)

That C240 also had the nicest 9-track drive in the room. Most of my tape mounts 
were on the TU77 next to the VAX-11/780 (or maybe 785?), but I always liked 
working with that drive on the C240. I no longer recall which company 
manufactured its transport, but it was really fast.

> 
> I¹m getting a C240 two weeks from now. Between the C220, the C240, and the
> two C1s, I hope to be able to  get at least one Convex up and running
> ConvexOS.

That is really cool, and it sounds like you have all of your barn heating needs 
sorted out, too!


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

Re: Convex documentation online (C220 arrived)

[Mark J. Blair via cctalk]

Wow! I fondly remember the air exhaust from the power supply cabinet of the 
Convex C240 as being the warmest spot in the UCI computer room at 6AM, when the 
main Computer Science building A/C turned on and the computer room temperature 
plummeted. Maybe I should finally learn how to use one for its designed 
purpose? :)


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

Re: Cipher F880 with S100 interface card on local CL

[Mark J. Blair via cctalk]

> On Jul 10, 2017, at 09:15, Jon Elson via cctalk  wrote:
> 
> You could do a controller using the Beagle Bone black and the PRU devices, 
> which are 200 MHz 32-bit microcontrollers built into the Bone's processor.

That's the scheme I have in mind for making a Pertec interface one of these 
days. Of course, that's far down on my list of projects, so I won't complain if 
somebody else gets around to it first, and shares the hardware and software 
designs.

> I used an FPGA to do a formatted Pertec interface for my CDC Keystone drives, 
> but if I were to do it today, I would use the Beagle Bone.

I was previously planning to so that, and I still think that the FPGA approach 
would feel more natural to me than using the PRUs. But the Beaglebone seems 
like a much more economical approach. I'd need a processor to control it, an SD 
card and/or USB and/or network interface to get data and commands on and off, 
and driver stacks for all of that stuff. I could also get there with a Xilinx 
Zynq family device, but at 2x or more cost vs. a BeagleBone.


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

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 3:34 PM, jim stephens via cctalk  
> wrote:
> 
> 
> 
> On 7/6/2017 10:59 AM, Chuck Guzis via cctalk wrote:
>> Go figure.  Perhaps nobody owns a line printer that takes continuous
>> forms any more.
> I'm moving a Data Products 2230 this weekend.

Oooh, congratulations! I don't have a proper line printer yet, though I have a 
number of small dot matrix printers and I can print on wide greenbar with my 
LA120. I still hold out hope that I might find an LP32 someday to go with my 
11/730.

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

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 11:50 AM, Chuck Guzis via cctalk  
> wrote:
> 
> I've uploaded the files to my Box account:
> 
> https://app.box.com/s/liuljs46noaz58grdwuj170mjh66qzm8
> 
> I have the permission of the owner to share these.  Note that many of
> them depend upon first-character FORTRAN carriage control.

I have downloaded the archive. I'll need to see if I have anything sitting 
around that understands the carriage control, or else hack up a quick script to 
convert the files to plain line-delimited text. Thanks!


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

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 12:42 PM, Rob Jarratt  wrote:
> 
> 
> Why not give baking a go then? Or have I missed something? I would of course
> recommend trying with an unimportant tape first until you get a time and
> temperature that works for your setup.

Oh, it's on my get-around-to-it list. I'll start out experimenting with that 
random tape that has already shed a lot of oxide. If I can get it to load and 
rewind without sticking to the heads and rollers, then I'll know I have the 
parameters worked out.


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