test-drb March 2008

test-drb@ccmp.vtda.org

209 participants
369 discussions

Start a nNew thread

atc-510 simulator

by fwujek＠cox.net

Hi Joe, Was wondering if you ran across or have a Service Manual for the ATC-510??? Thank you, Fred H. Wujek

16 years, 2 months

front panel display for a modern PC

by slawmaster＠gmail.com

I'd really like to have something like one of the old mainframe/minicomputer control panels for my PC, but I'm just not sure how to implement it. Anybody here tried something like that? Ideally, you could power it on, see registers, toggle stuff into memory, have lights for interrupts, that kind of thing. Yeah, I know, as soon as I bring up an operating system, the ability to toggle things into memory would be rather dangerous, but I just can't resist the charm of the idea :) So... doable? Impossible? Improbable? John -- Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

16 years, 2 months

More on my CDC (MPI) floppy drive

by ard＠p850ug1.demon.co.uk

Yo umay rememebr my recent posting aasking for information on the damper assembly on the head carriage of a full-height 5.25" MPI floppy drive. I've done a little more work on it. Firstly, it appears the damper ron was glued ot the head carriage. Since this makes it very hard to work on (fitting the tension abnd is difficult at the best of times!), I cleaned out the holes, and drilled (1.6mm) and tapped (M2) an extra hole in each of the plasic rackets that hold this rod, 0.2" away from the existikng hole. I then screwed little rass plates in place to keep the rod in. Secondly, I've assembled (but not aligned) the positioned. Fittlng the tensio band ais a pain, I now think that little O-ring I found on one of the pins is an assembly aid to keep the tension band on that pin when you're trying to fit the other end in place. I will order some more O-rings (the pins are 1.5mm diameter, BTW) and see how I get on. Thirdly, I've had the positioner running on a disk exerciser. WIth a 6ms step rate (which seems about right), it sounds _much_ rougher with the damer wheight not fitted. Even without any grease (other than that I've not managed to clean out) on the assembly, fitting the weight makes it a lot smoother. Fourthly, I _still_ can't see how the grease is kept in place, and why it doesn't just leak all over everthing. -tony

16 years, 2 months

Dekatron article

by ard＠p850ug1.demon.co.uk

For those who've not seen it yet... In this month's Elektor magazine (or at least in the UK edition of it), there's a 2-page 'Retrotronics' article giving a design for a Dekatron counter driving a nixie tube with 6J6 (ECC91) triodes as buffers. -tony

16 years, 2 months

HP-12531 C and D

by Tim＠Rikers.org

I have 4 HP-12531 cards. Two are have tabs labeled "HS TERMINAL" and 2 have labels "BUF'R'D TTY REG". Three of cards have 307.200 Khz crystals, and one of the non-HS boards has a 225.280 Khz crystal. >From what I read in: http://www.bitsavers.org/pdf/hp/21xx/interfaces/12531C.pdf and on: http://www.cs.ubc.ca/~hilpert/e/HP21xx/io12531BCD.html the only difference I can see between the C and the D is the crystal. Does anyone know of another difference? Ok, here's the big one. Anyone know where to get another 307.200 Khz crystal? :) -- Tim Riker - http://Rikers.org/ - TimR at Debian.org Embedded Linux Technologist - http://eLinux.org/ BZFlag maintainer - http://BZFlag.org/ - for fun!

16 years, 2 months

Selectric trouble

by Watzman＠neo.rr.com

I am not a selectric guru, but I have one and I think that the most likely cause is that the lubricant has dried out, isn't lubricating and in fact is acting like glue or adhesive. The "right" way to fix this is to have the whole mechanism immersed in a bath of solvent (quite a few things have to be disassembled and removed before this is done) to clean off the old lubricant, and then relubricated afterwards. This used to be common, but there are not many places now that still do it and it's expensive (probably a couple hundred dollars). I have a full IBM service manual for the Selectric II, which is virtually identical to your machine, but I only have it in hard copy, not PDF, and it's bound. Perhaps there is a PDF copy of this manual on the 'net somewhere. A guy who did the immersion cleaning used to advertise his service on E-Bay, you might to a search there, or a google search. Barry Watzman Watzman at neo.rr.com PS - Actually I found the contact information for someone who was still doing this at least in 2006. His name is Rich Wiley, he is at 800-552-8592 and his E-Bay ID was coyote0153.

16 years, 2 months

1st stage loader for IMSAI - need ascii to binary

by aliensrcooluk＠yahoo.co.uk

YouTube doesn't stream. It slowly downloads the flash video files to the temporary internet files folder where it's usually named "FlaXX.tmp". The XX is usually a hex number depending on how many tmp files you have in there. The file is also (99% of the time) deleted the second you close the page it is linked to. The good thing is that you can watch the video before it's fully downloaded. A very good thing if you are on dial-up :) Does anyone have a list of retro video's on YouTube? I know most can be found by searching for the appropriate machine name, but not everyone has decent tags with there videos :( Regards, Andrew B aliensrcooluk at yahoo.co.uk woodelf <bfranchuk at jetnet.ab.ca> wrote: Right now I am trying to VIEW the %$@! You-Tube stuff. I hate streaming stuf on dial up. I don't think I will ever get more than the 1st few minutes of the UNIVAC stuff. Nothing like comparing almost 60 years of computing development. > Cheers, > Chuck >

16 years, 2 months

VAXstation/MicroVAX 2000 CPU/FPU overheating?

by ajp166＠bellatlantic.net

The same CPU and FPU are sued on the KA630cpu (uVAXII) and in early microvax3100s so any of them should compare. Is it possible that someone has overclocked the that uV2000??? FYI: gate leakage would kill the chips not make it run hot. The usual reasons for hot running are: Over voltage! Overclock Undercool Excessive bus loads (capacitive or resistive) Since the machine is a closed system for the most part the first is most likely and the others are least likely. I may add that over 60C is way too hot at the heatsink and the die due to thermal resistance will be hotter. I'm trying to pull down one of my uV2ks and fire it up. Allison > >Subject: Re: VAXstation/MicroVAX 2000 CPU/FPU overheating? > From: "Dave Dunfield" <dave06a at dunfield.com> > Date: Fri, 29 Feb 2008 08:18:31 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> I assume these CPU and FPU chips are MOS devices. Is it possile that >> excessive leakage across the gate oxide layer in some transsitors of that >> chip would cause it to run hot, but still work? I'm pretty sure I've seen >> chips that seem to work, but get hot and then stop working, althoguh >> cooling them with freezer spray keeps them running. And these were not >> chips driving high pwoer laods -- they were things like the clock/timer >> microcontroller in a VCR. > >Yes, I'm wondering if it's something like that, however how likely is it >that both devices would experience the same fairly-uncommon failure mode >at the same time? > >Perhaps I've been engaging in the persuit of an undomesticated ornithoid... > >Is it possible that the devices normally run this hot, and the failure is >occuring for another reason (possibly a side effect of the heat, as cooling >them does allow it to keep running). > >Allison said "they do run hot" - does anyone know how hot? > >I did some further tests last night - I dug out my thermocouple and made >some actual heat measurements with the system assembled, but with the color >frame buffer removed - there should be better airflow, and this appears to >be the case, since the machine did not die after 10 minites of operation. > >Ambient temp was measureing about 25 degrees C at the start of the test. >>From power on, the CPU and FPU rose rapidly (within 3-4 minites) to >the 70C range, then more slowly rose to temperatures of 76C for the CPU >and 82C for the FPU after 10 mins. At this temperature they seemed to be >getting stable - having done nearly 1-1/2 mins without an increase. It's >possible/likely that they would climb anothe few degrees in extended >operation. > >Once this temperature was reached, I held the system in RESET, and >observed that the temps dropped back after a few minites to about 64C >for the CPU and 68C for the FPU. > >To my mind, a processor running at 80C is damn hot - most of the embedded >devices I work with list absolute maximum running temperature as 70C or >75C - but perhaps the DEC devices are designed to run hotter - I note the >Intel 486 datasheet lists absolute maximum (under bias) as 110C ... > >Anyone on the list with a VS 2000 or uVAX 2000 that can do some temperature >measurements? > >Dave > >-- >dave06a (at) Dave Dunfield >dunfield (dot) Firmware development services & tools: www.dunfield.com >com Collector of vintage computing equipment: > http://www.classiccmp.org/dunfield/index.html

16 years, 2 months

Speaking of PPT (was: Re: Friden Flexowriter)

by roger.holmes＠microspot.co.uk

On 28 Feb, 2008, at 08:16, cctalk-request at classiccmp.org wrote: > > Message: 25 > Date: Wed, 27 Feb 2008 23:38:42 -0800 > From: "Chuck Guzis" <cclist at sydex.com> > Subject: Re: Speaking of PPT (was: Re: Friden Flexowriter) > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: <47C5F482.14707.21D48412 at cclist.sydex.com> > Content-Type: text/plain; charset=US-ASCII > > On 28 Feb 2008 at 7:49, Jos Dreesen / Marian Capel wrote: > >> The latest HP papertape reader I sold on Ebay fetched all of 5 >> Euros...... > > I know that PPT readers can really zip right along, but what's the > fastest perforator ever made? Laser-driven, maybe? Catching up on old messages. The manuals for my ICT 1301 refer to the standard paper tape punch, and it ran at 300 characters per second and had a check reading station to verify every character punched before winding the tape onto a reel. Unfortunately I don't have one of them but my 1301 does still have one (of two) of the Elliott tape readers which runs at 1000 characters per second and which have a tape un-roller to prevent any drag on the reader itself. At 1000cps, the tape comes out almost horizontal from the reader and a bin has to be positioned correctly to catch it. Even at full speed, the reader can stop on character unlike the earlier Elliott tape readers, which was why when I worked for Marconi-Elliott Avionics, all text tapes were punched with four null characters after every line termination (ASCII CR-LF or Flexowriter newline). Binary tapes were expected to be read all in one go without stopping. My own Flexowriters have round military style Cannon plugs for I/O and use 110v signal levels designed for relay logic. A previous owner of my 1301 has grafted on a large Vero board full of discrete components, TTL and relays to drive one of the Flexowriters for output, and an old ICT keypunch keyboard for input as well as a smaller board to output to a Teletype BRPE (100 cps) paper tape punch. The non standard online Flexowriter and keyboard are currently disconnected and I control the 1301 the same way as 99% of 1301s were controlled via the control panel, which is, I estimate, 4 feet wide by 2.5 feet high. Most programs are small and I key them in through the front panel as I can't find anyone to repair my IBM keypunch.

16 years, 2 months

WaveMate Bullet

by lynchaj＠yahoo.com

Hi All, Thanks to some very generous help from a few friends, I have been able to finally locate a boot disk for the WaveMate Bullet. In addition, I was able to repair the unit and now it boots and seems to be working at least to some degree. Along the way, I gathered up a lot of disk images, documentation, files, and assorted other items related to the WaveMate Bullet. As this is a rather unusual vintage computer I am considering storing this cache of stuff online someplace to help any other prospective WaveMate Bullet owners. My first reaction is to start another Yahoo! Group but I know a lot of people here absolutely hate those so I thought I'd poll the list to see if anyone could suggest a more palatable alternative. My requirements are simple; just a small amount of file storage, a simple web interface, and a mailing list. Thanks! Andrew Lynch

16 years, 2 months

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb March 2008