test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

> From: W2HX > I filter on category "Computers/tablets & Networking." It might not have > shown up in your search if you searching in "Vintage Computing" > category. Oh, I forgot to mention: I always search in 'All Categories' precisely to avoid misfiled entries (like this one). (For a while it was defaulting to "Vintage Computing" for the "PDP-11" and "DEC Digital" searches, which I had to manually reset to 'All Categories'.) But that's not it: go into the eBait search, enter "PDP-11", and select 'Sold Items", it's not there; add "parts" to the search, and up it pops! WTF?!?!? Noel

8 years, 3 months

Identifying bad RAM on Amiga 1000 WCS board

by ethan.dicks＠gmail.com

Hi, All, I've been doing component-level diagnosis of a bad Amiga 1000 WCS board and since I was unable to find this information anywhere, I thought I'd post it to the list so that it's in the hands of more than one person. For an Amiga 1000 that starts up with a turquoise screen and never asks for Kickstart, it means that the WCS RAM test has failed. Common causes are one or more bad 4464 DRAM chips on the WCS board or a bad PAL. I don't happen to have the PAL equations but I did spend some time with a sick Amiga 1000, a Fluke 9010A and a cheap digital scope. There are hand-drawn schematics floating around but they don't appear to match the production hardware in either part placement or completeness (the schematics describe 2 PALs, DAUGCAS and DAUGEN, but the production hardware has two additional PALs, DPALCAS and DPALEN, for one specific example). If one has a Fluke 9010A and 68000 pod, one can test the WCS RAM by pressing [RUN UUT] and turning on the Amiga and waiting a second or two for the ROMs to set the right memory map bits to make the WCS writable. One can then do simple [READ] and [WRITE] tests to the Amiga at $FC0000-$FFFFFF and even run a [RAM SHORT] on part or all of that range (a RAM SHORT test on 256Kbytes will take more than a few minutes). The memory itself is a bank of 8 4464/50464 64Kx4 DRAMs at U1B-U1E and U2B-U2E, arranged sensibly in two banks of 128Kbytes. The chips in row 2 are the lower half ($FC0000-$FDFFFF) and the chips in row 1 are the upper half ($FE0000-$FFFFFF). The individual bits are arranged as follows: U1E/U2E $000F D0-D3 U1D/U2D $00F0 D4-D7 U1C/U2C $0F00 D8-D11 U1B/U2B $F000 D12-D15 For those that want to trace individual bits the order on each DRAM is pin-3, pin-2, pin-15, pin-17 which is slightly off the given order on the 4464 datasheet of 2,3,15,17. By way of verification, the WCS board I'm repairing failed the RAM test with bad bits at $F000 when I pulled the defective chip from position U1B. The same chip failed testing in a Ming HT-21 "Handy Tester" DIP logic and DRAM tester (but passed when tested as a 4416, because the fault was not in the first 25% of the memory cells). -ethan

8 years, 3 months

PDP 8i in NJ on Ebay

by billdegnan＠gmail.com

https://www.ebay.com/itm/Pdp-8i-Computer-With-Tape-Readers/253588804132 I went to check this out....this is they guy with 10 PDP 8i's in a barn. Looks like he cleaned one up. I have more pictures on my web site, I had posted them here before, but I thought they were overpriced http://vintagecomputer.net/pictures/2016/PDP8i/ b

8 years, 3 months

New cooling cans for 80386 and 80486

by sales＠elecplus.com

We bought these years ago in bulk. Turns out there are 78 left! New 40mm fans on a 50mm base. https://www.elecshopper.com/fans-and-heatsinks/silent-systems-fan-40-01154-4 .html Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 830-370-3239 cell sales at elecplus.com AOL IM elcpls --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

8 years, 3 months

Rick Dickinson, ZX Spectrum designer, RIP

by lproven＠gmail.com

A lengthy interview with the later great Rick Dickinson, product designer of basically every Sinclair computer, who sadly died of cancer on Tuesday. https://medium.com/@ghalfacree/an-interview-with-rick-dickinson-3fea60537338 He not only did the ZX 80, ZX 81, ZX Spectrum and the QL, but also the Z88, the Spectrum Next and others -- along with a lot of other stuff. I know this is a rather USA-centric list, so probably most of you started off with things like the Apple II, the first sub-$1000 home computer. But in Britain and Europe back then, we were a lot poorer, and $1000 was an impossibly large amount of money -- many months of pay in a good job. I think in my early home-computer days, I never saw a single Apple II -- they were exotic, expensive foreign machines. I have only seen them in recent years, as collectible antiques. In the UK, the revolution was the first sub-?100 home computer, the ZX 81. I first used a Commodore PET. Later, a few of my richer friends had Commodore 64s. The super-wealthy might have a BBC Micro. In either case, a working setup with mass storage -- floppy drives -- was nearing ?1000. Nobody owned a _monitor_ -- they were exotica for professionals. Whereas a Spectrum with a Microdrive was a quarter of that and a highly usable system, with tens of thousands of games, plus mutiple programming languages, word processors, databases and more. I think if you ask virtually any British person in their late 30s, 40s or 50s, in anything connected with IT, what their first computer was, the answer would be a ZX 81 or a ZX Spectrum. It was the single range of machines that drove the entire computer revolution over here, and also in the form of a myriad clones in the Communist Bloc. Later, imitators came along -- the Oric (6502) and Dragon (6809) ranges, for instance. And of course there were many machines that aspired to be better: Memotech. Camputers Lynx, Elan Enterprise, etc. All flopped to some degree. The only thing that displaced Sinclair was Amstrad, who made more expensive computers but with much better specifications -- an integrated tape drive, or floppies, even a printer, and a real monitor. They cost more but still less than Commodore or Acorn: you got a lot for your money. Amstrad eventually bought Sinclair's models and name, and later still, it launched the first _cheap_ PC clones and kick-started the IBM-compatible industry over here. But it did it standing on Sinclair's shoulders. Part of the joy of Sinclair machines (like Apple and Commodore) was their very distinctive look -- black, slablike, with tiny discrete bits of colour, unlike the grey or beige boxes of virtually all the competition. And that was down to Rick Dickinson, who only discovered years later how he had inspired whole generations of people. -- Liam Proven ? Profile: https://about.me/liamproven Email: lproven at cix.co.uk ? Google Mail/Hangouts/Plus: lproven at gmail.com Twitter/Facebook/Flickr: lproven ? Skype/LinkedIn: liamproven UK: +44 7939-087884 ? ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053

8 years, 3 months

Identifying bad RAM on Amiga 1000 WCS board

by Richard.Sheppard＠telus.com

> There are hand-drawn schematics floating around but they don't appear > to match the production hardware There is a service manual - "Amiga Computer Model 1000 Preliminary Component Level Repair PN 314038-02" which does show those PALs on page 1-25 "Amiga piggyback PCB assy #327139" Richard Sheppard

8 years, 3 months

SPARCserver 600 PROMs

by dennis.grevenstein＠gmail.com

Hi, I am looking for years now for bootproms for a SPARCserver 600. I have been able to obtain 2.14 prom images and they work. This allows upgrading the CPUs to SuperSPARC I. However, you need 2.14.3 to install faster CPUs and some slightly different 2.14.3H to install HyperSPARC CPUs. There is a set of images going around in archives, this it?s actually 2.14, rather than 2.14.3. Does anyone here have prom images of 2.14.3 or 2.14.3H? thanks, Dennis -- Don't suffer from insanity... Enjoy every minute of it.

8 years, 3 months

TRS-80 Fragmentation

by oltmansg＠gmail.com

It is obvious that the TRS-80 line of computers suffered severe fragmentation with differing architectures: TRS-80 Model I, III, and 4(P) are all obviously of a mostly compatible architecture. TRS-80 Model II and 16, 68k based "business" machines TRS-80 CoCo I, II, III (Dragon) TRS-80 PC-x, various rebadged machines from Sharp, Panasonic, or Casio TRS-80 MC-10 (a Matra Alice) TRS-80 Model 100, 102, 200 (rebadged Kyoceras) So, obviously there were several good sellers in there, and of course for every good seller there's at least one bad seller. The PC line were mostly replacements for calculators that were programmable, and the Model 100 derivatives were mostly used as appliances rather than general purpose machines. Aside from that, it seems like Tandy more than most went off in the weeds with their own wide variety of machines instead of settling on a common architecture. Do you think that if they had, say, revised and extended the Model I system to color/80 column that the rest would have been mostly redundant?

8 years, 3 months

Visiting Boston - Classic computer recommendations (Huw Davies)

by michael.99.thompson＠gmail.com

> > Date: Thu, 26 Apr 2018 19:17:18 +1000 > From: Huw Davies <huw.davies at kerberos.davies.net.au> > Subject: Visiting Boston - Classic computer recommendations > > I?m in Boston MA (technically Canton) for the next three weeks (April 29 > to May 19). Looking for recommendations on classic computer/classic > car/sailing things of interest to do on the weekends. > > Huw Davies | e-mail: Huw.Davies at kerberos.davies.net.au > Melbourne | "If soccer was meant to be played in the > Australia | air, the sky would be painted green" > > Please visit us at the Rhode Island Computer Museum. About 60 miles south of boaton. http://www.ricomputermuseum.org/ We will be working in the Learning Lab on Saturdays, and can take you to the warehouse for a tour of the static storage. There are classic car museums not far away in Newport and Middletown, and lots of sail boats in Newport. -- Michael Thompson

8 years, 3 months

Looking for Heath H-29 operation manual and schematic

by fritzm＠fritzm.org

Al, following up on this thread from February, in case you are still looking, I just came across my copies of: - Z-29 Uers's & Technical Guide (1983) - Z-29 ASCII character and escape code chart Despite the claim to be a "Technical" guide, the above is really more of a user manual, containing in-depth description of control codes and operating modes, but not much else (no circuit descriptions nor schematics). I'll be showing at VCF West in August, and happy to bring these along and donate them to the scan queue if you are still looking for them? cheers, --FritzM.

8 years, 3 months

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