test-drb July 2021

test-drb@ccmp.vtda.org

98 participants
64 discussions

by a.carlini＠ntlworld.com

I have three AlphaServer 2100 systems in storage in the UK (Oxfordshire). The storage, however, is due to be demolished (soon, but no fixed date). I won't have room to store these three systems, so if anyone would be interested in offering them a home, then please get in touch! I can probably get some pictures in the next day or two. These systems were SMP Alphas and could sport as many as 4 CPUs. I'm not sure of the configuration of these systems but I can probably find that out soon. They have not been run since ~2003 so they may be in need of some TLC. OTOH they are not rusted to death so you have a chance of getting them back to life. Just so you know what you might be dealing with these systems are about: 700mm H x 430mm W x 810mm L. I can't find the weight in any of my references right now but they are very heavy. Three people can move them up a slight slope with some effort but you would not successfully lift it into a car (assuming that it would fit). I'm planning to dismantle them to move them (i.e. remove PSU/PSUs etc. until they are light enough to move). A tail-lift would probably be the sane way to go (and is, indeed, how they got to their current location. I'm hoping that someone can step forward and offer one or more of these machines a new home. Please contact me off-list (once you're sure you understand what you are getting into :-)). Antonio -- Antonio Carlini antonio at acarlini.com

2 years, 4 months

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

by cctalk＠beyondthepale.ie

The recent discussion on BSC protocol prompted me to dig out my Microvax 3100 with DSH32 synchronous serial interface. It had been idle in storage for several years and it wouldn't power up, only giving a brief flash on the diagnostic LEDs and a quick twitch of the fans. There was a slight smell, like the stale air that comes out of a deflating tyre. I took out the H7821 power supply and found that five identical brown 1800uF 25V electrolytic capacitors on the output side had leaked. The SCSI disk enclosure where the machine's system disk lives required several power cycles to get it to run at all and it died as soon as the disk tried to spin up. It turned out to also contain a H7821 power supply which had a similar issue with the same five brown capacitors, although not as extensive as in the main unit. I found a second disk enclosure which had seen little use and grabbed the power supply out of that to put in the MicroVAX. It worked well enough to test with but there was a ring of goo around the bottom of one of the brown capacitors which was worst affected in the other units. Time to order a batch of replacement capacitors and figure out what else has been damaged. While it is not the worst I have seen, access to these power supplies for repairs is quite difficult and it is really difficult to debug them safely while they are running with the cover off :-( If anyone has anything with H7821 power supplies in them, I suggest checking on these capacitors. If anything with these power supplies is in storage, I suggest ensuring it is stored the normal way up as this should limit the ability of the goo to escape and spread around the power supply. And there I was thought I was being safe enough by removing the nicad battery packs some years ago... Regards, Peter Coghlan.

2 years, 7 months

VAX4000 VLC diagnostics/console

by binarydinosaurs＠gmail.com

Hi folks, I'm testing a little BlueSCSI adapter (BlueSCSI <https://scsi.blue/>) which while being aimed at 68K Macs should also work as an 8 bit target for older VAXen, it's a newer cheaper SCSI2SD solution and I should point out it works as intended on a Mac Plus so the module itself is fine. Nobody appears to have tested on small VAXen yet so tonight I dug out my VLC to give it a go. Powering up with nothing attached apart from an MMJ/H8571 cable I get nothing on the console, I'm using PuTTY via a genuine COM1 port on a PC which is one level above what I used last time I powered the machine up (FTDI USB adapter to a laptop). Diagnostic LEDs cycle through the tests and end up at '1111 0011' which according to the manual is 'entering the console program'. Clearly the DALLAS has passed the TOY tests, but if it's not happy would that stop the console displaying? It doesn't matter how I set S3, next step I guess is to hook it up to a 'proper' VT. Cheers, -- Adrian Graham Owner of Binary Dinosaurs, the UK's biggest private home computer collection? t: @binarydinosaurs f: facebook.com/binarydinosaurs w: www.binarydinosaurs.co.uk

2 years, 11 months

Replicating IBM SLT/MST card interconnect

by stepleton＠gmail.com

Hi cctalk, I'm looking to replicate the 24-contact connector system that IBM used on SLT and MST cards for many years. Has anyone done this before? The best photos of this connector that I can find online are on this page: http://techandtrouble.blogspot.com/2014/04/happy-50th-system360-pt5-anatomy… I haven't searched Bitsavers documentation extensively for IBM specifications, but I've seen some details around page 54 of this document: http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLog… I'm interested in reproducing both polarities of this connector: plug and socket. Also, even though the most familiar use of this connector is for board-to-board interconnect, I'm most interested in wire-to-board interconnect. IBM used this method for DC power connectors in its 5100, 5110, and 5120 computers. Here are images of this specific connector: http://stepleton.com/connector/ taken as still images from a YouTube video on the IBM 5120 by Jerry Walker ( https://www.youtube.com/c/JerryWalker-JMPrecision/videos). I've designed and built a device that monitors DC power supply voltages for overvoltage and undervoltage excursions and cuts off all power rails if any voltage goes out of spec. I hope to use it to protect my own IBM 5100 from major power supply faults like the one CuriousMarc encountered with his 9825T: https://www.youtube.com/watch?v=b-eN93L6yX8 In order to put my device between my 5100's power supply and the logic card backplane, I need to recreate a plug and a socket so that I can fashion a cable that goes out to my device. If anyone has created dependable modern versions of these connectors, would you mind sharing any pointers? Thanks for any help, --Tom

3 years

Ian Hirschsohn - DISSPLA, Superset Inc. and sad news

by jfoust＠threedee.com

At 12:56 AM 7/31/2021, Randy Dawson via cctalk wrote: >As some here know, I collect some dusty deck fortran graphics. We have MOVIE.BYU up and running! (Thanks Douglas Taylor and Emanuel Steibler). Once I was in the business of making 3D file format translators, and I still have code that runs under Windows that can read and write Movie.BYU format. - John

3 years

IBM PC diagnostics disks

by rsmilward＠frontier.com

I have these 5-1/4" diagnostics disks but no need for them. If you're interested, I'll send them to you for the cost of the postage from Durham, NC. * Diagnostics for IBM Personal Computer AT, ver. 2.03 copyright 1981, 1986 maroon disk label, p/n 6183111 * Advanced Diagnostics, ver. 2.20, copyright 1981, 1986 dark blue label, p/n 6139804 They are in excellent physical condition. Sorry, I don't have the manuals. (I used to work for a ComputerLand store in '81-'82 and probably acquired them there.) They might be available for download somewhere, but these are the physical, displayable versions. **Richard

3 years

Skew vs. interleave

by mhs.stein＠gmail.com

There's a small discussion on S100computers about the terms 'skew' and 'interleave'. In CP/M documentation 'skew' refers to what's usually called interleave these days, i.e. offsetting sectors on a track to compensate for the fact that by the time the computer has processed a given sector the next one has already passed by, so that the computer has to wait an entire revolution for it to pass by the head again; in other documentation as in Chuck's 22disk for example this is also called 'interleave'. However, in later documentation the meaning of 'skew' seems to have changed to refer to the offset of sectors between adjacent tracks to compensate for the time required to step the head. Can anyone (Fred, Chuck?) shed some light on this apparent double meaning of 'skew'? And if skew was used to describe sector interleave then what was the offsetting of sectors between tracks called? Inquiring minds need to know ;-) m

3 years

Branching the thread away from Compaq deskpro boards: "What We Have Lost"

by lproven＠gmail.com

This was a talk at a recent Chaos Computer Club congress: https://media.ccc.de/v/rc3-525180-what_have_we_lost#t=1707 ? We have ended up in a world where UNIX and Windows have taken over, and most people have never experienced anything else. Over the years, though, many other system designs have come and gone, and some of those systems have had neat ideas that were nevertheless not enough to achieve commercial success. We will take you on a tour of a variety of those systems, talking about what makes them special. In particular, we'll discuss IBM i, with emphasis on the Single Level Store, TIMI, and block terminals Interlisp, the Lisp Machine with the interface of Smalltalk OpenGenera, with a unique approach to UI design TRON, Japan's ambitious OS standard More may be added as time permits. ? It talks about Lisp Machine OSes, which interest me, but I especially liked that there's a demo of Interlisp as well as the better-known Symbolics OpenGenera. Unlike Genera, Interlisp is now FOSS and there is an effort afoot to port it to modern OSes and hardware and revive it as a Lisp IDE. There's also a not-very-inspiring but all too rare demo of IBM i. It's not pretty but this descendant of OS/400 is the last living single-level store in active maintenance and production. But the big thing that made me link to this after the discussion of DOS/V, Chinese Windows 3.2 and Japanese DR-DOS and DR GEM, was the demo of the final version of Japan's TRON OS. Most people have never heard of TRON but it was extraordinarily widely-used, embedded in billions of consumer electronics products. Well, there was also a desktop-PC version, with its own very rich object-oriented GUI, and this talk contains the only demo of it I've ever seen. -- Liam Proven ? Profile: https://about.me/liamproven Email: lproven at cix.co.uk ? gMail/gTalk/gHangouts: lproven at gmail.com Twitter/Facebook/LinkedIn/Flickr: lproven ? Skype: liamproven UK: +44 7939-087884 ? ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053

3 years

Unidentified IBM Module / Package

by coryheisterkamp＠gmail.com

Does anyone recognize these IBM modules? My gut says late 50?s based on the transistor packages and font. Perhaps for a contract or military system? Thanks- Cory https://www.dropbox.com/s/izitf1lmjqwcbuo/IBM1.jpg?dl=0 https://www.dropbox.com/s/dq8macaubrechkz/IBM2.jpg?dl=0

3 years

Help reading a 9 track tape

by jimliu＠umich.edu

Hi, I have been lurking for a few years, but thought I'd finally speak up as I just received a 9 track tape purportedly containing the source code to Schoonschip (https://en.wikipedia.org/wiki/Schoonschip). This is a 2400' reel recorded at 1600 bpi based on the labels, and a cursory examination suggests that it is still in pretty good shape (although I am not sure how it was stored over the years). Here is a picture of the tape: https://drive.google.com/file/d/1JgY8QdVDchxubUz39jYn86gEczSvFhcZ/view?usp=… We no longer have any equipment that can read the tape, so I was wondering if anyone may be willing to help or if anyone had suggestions on where to go to get it read. Thanks! - jim -- James T. Liu, Professor of Physics 3409 Randall Laboratory, 450 Church Street, Ann Arbor, MI 48109-1040 Tel: 734 763-4314 Fax: 734 763-2213 Email: jimliu at umich.edu

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test-drb July 2021