test-drb April 2018

test-drb@ccmp.vtda.org

128 participants
123 discussions

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, 1 month

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, 1 month

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, 1 month

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, 1 month

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, 1 month

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, 1 month

Amusing IBM test system model

by cctalk＠ibmjunkman.com

I also have a few others listed: ADINTS https://www.ebay.com/itm/132588526929 IBM 1401/707 https://www.ebay.com/itm/132581434367 IBM System/3 https://www.ebay.com/itm/132593475814 Yet to be listed is a 650 and 2 suitcases of System/360 Model 70 models used in the 1964 Worlds Fair.

8 years, 1 month

Restoring rubber keyboard on a logic analyzer

by shadoooo＠gmail.com

Hello, this kind of keyboards was made using small pieces of conductive rubber to close the circuit designed on the PCB. The rubber was an uniform compound, so even with severe usage, i.e. high consumption, the conductivity remained constant. However, in more recent / cheaper products, the rubber is the same for the whole keyboard, i.e. simple insulating silicone rubber. The conductive surface is only painted over the silicone. No doubt it comes away faster... In this case, cleaning with alcohol just removes the remaining paint, referring the keyboard useless. The solution is simple: cover the key contacts with something conductive. I know that conductive paint is sold somewhere, but it's pricey and don't think it would last much... The cheapo solution is to cut small pieces of aluminum foil, and glue it to the rubber. Given that the keyboard is almost always made by silicone, I always use silicone glue to assure the sickness. Be careful to put a very thin layer of it only over the center of the foil, then put it in place and press a bit around with the fingertip to let it take the shape of the contract. Too much silicone would come out when pressed and would cover the graphite on the PCB. This method worked well with several TV remote controls. I could suggest you to try with one key, then let the silicone to dry before remounting the keyboard, then check the result and eventually repeat on other keys. Andrea

8 years, 1 month

Visiting Boston - Classic computer recommendations

by huw.davies＠kerberos.davies.net.au

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"

8 years, 1 month

Anyone fancy lending out a Replica I for a few weeks?

by brain＠jbrain.com

I would like to ensure my PS2Encoder project works on the Apple I, but I have no unit to test with. Alternatively, anyone out there with access to an Apple I/Replica I/functional equivalent who can test and reprogram an Atmel ATMEGA88 or ATMEGA168? Jim -- Jim Brain brain at jbrain.com www.jbrain.com

8 years, 1 month

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test-drb April 2018