test-drb August 2004

test-drb@ccmp.vtda.org

283 participants
661 discussions

Fixed! RE: Where to see vintage computers in (your town here) ???

by evan947＠yahoo.com

The site now works properly on Mozilla and Navigator. Personally I use Opera, where it also works fine. For those who missed the original email, here's the scoop: I recently update the site http://news.computercollector.com (the informational page for my weekly email magazine), and there's now a new "On the road" section where you can find places to see vintage computers all around America. - Evan

20 years, 4 months

Where to see vintage computers in (your town here) ???

by news＠computercollector.com

Hello fellow collectors, There's a new resource for finding places to see antique computers, at the (updated) web site of the Computer Collector E-mail Newsletter. The URL remains the same as before (http://news.computercollector.com) but now there's a much improved section called "On the road" with a directory of museums and stores. I created this page because I keep seeing the same question appear on classiccmp over and over again, and then I started getting the same question >from newsletter readers too. Currently there are 53 listings. Mostly they are museums (some for adults and some for children) and there are some stores too. In the future, I plan to add more listings of electronics and surplus stores, swap meets locations, and bookstores. The "On the road" directory and the newsletter itself, which still publishes every Monday(-ish), are and will always remain free. However, I do ask for your help. If you know of any museums, stores that sell old computers or relevant parts, swap meets, or science/technology bookstores, no matter how small or out-of-the-way they are, then please tell me. For now the directory is sorted by U.S. state, but when it becomes more full, I'll probably make it searchable and also separated by category (museum, store, etc.)... eventually I'll add non-U.S. locations too. Another idea I have is to post reviews from people who've been to the locations in person. I hope this helps! - Evan

20 years, 4 months

PET problem SOLVED!

by dave04a＠dunfield.com

Ethan, Dwight (and anyone else who helped), Thanks for all the help - I've solved it and it works! Turns out it was NOT the ROM's -- After my last post I got to thinking that the PET ROM's are probably fused type, and wouldn't go marginal like an EPROM, so I focused on the RAM - sure enough, testing again, and I found that bit 1 of location $11 was stuck at zero (I'm positive I tried it before and it seemed to work - bit the funky PET monitor with it's exact # of spaces required was causing me some grief!) Anway, when 01 got incremented, instead of 02, it got 00 - this was hanging the search for end of RAM, which never incremented the high byte and therefore never traped at 32k.. Checking the Schematic, bit 1 of the low memory bank is U17 - pulled it, put in a socket (always!) and stuffed another 4116 - voila!!! it came right up! Also figured out the startup "noise" mystery (such unanswered questions "bug" me), turns out the PORTA bit 7, which is used for the DIAG input is also used to control the speaker (it was right on the schematic once I looked for it - duh) - pulling this line low disabled the speaker. Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Vintage computing equipment collector. http://www.parse.com/~ddunfield/museum/index.html

20 years, 4 months

Custom made front panels

by sloboyko＠yahoo.com

I've had Front Panel Express make some things and I think it's worth the price. Real quality work, and nearly what you see on your screen is what you get >from UPS. ===== -Steve Loboyko Incredible wisdom actually found in a commerical fortune cookie: "When small men cast long shadows, then it is very late in the day." Website: http://juliepalooza.8m.com/sl __________________________________ Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers! http://promotions.yahoo.com/new_mail

20 years, 4 months

Let's develop an open-source media archive standard

by mmcfadden＠cmh.edu

If someone is going to make the effort to decode the information from the original computer media into the archive standard then if the data is 10 or 100 times larger than the original should not be an issue. The same is true for costs. I have seen too many systems where there was a perceived decision that it would be too costly to "do it right". The idea is to take a copy of a program or data and convert it/archive it once and know that it is then saved. Think of the following; Stone once was expensive so clay tablets were used. Papyrus was expensive so wax tablets were used At one time paper was too expensive so it was not used chalk on a board was used instead. Later pulp paper was cheaper and acid free paper was expensive. Punch cards once were cheap Mark Sense forms Magnetic tape Magnetic disk Optical disk CD-ROM DVD The "best" real long-term media that I can think of is "eye ball" readable. Think Rosetta stone. Do you want to use Big-Indian, Little-Indian, Intel, Motorola, Cyrillic, cuneiform, hieroglyphs, binary, hex, octal RAD50, left-to-right, right-to-left, Chinese, Japanese, English, Pig Latin, Latin, Spanish, Old English, Old Latin, Norse, Mayan or Esperanto? I have heard that the Mormon Church is using iridium disks inscribed with an ion writer, it may take a magnifying glass but it's readable. It's supposed to last 1,000 years. This may be slightly sacrilegious. We will then need a "priesthood" of fanatical zealots to protect the archived data for posterity. I nominate Sellam to be the patron saint of data retention. Tony can be the patron saint of hardware restoration. I'll be friar Mike hunched over a lectern transcribing data with an ion writer. Mike

20 years, 4 months

RQZX1 setup?

by doc＠mdrconsult.com

I'm trying to find documentation on an RQZX1 Qbus SCSI controller. I'd like to know the dip switch settings, and especially how to access the ROM-based configuration tool. Any help would be sincerely appreciated. Doc Shipley

20 years, 4 months

He shoots... he scores!

by jwest＠classiccmp.org

Just obtained an M4 Data tape drive, model 9914 (800/1600/3200/6250)... just pulled from working service...desktop enclosure... $50 bucks :) I believe it's Differential, not single ended. I haven't kept up with PC technology (hooking this to a PC). Is this older Differential the same as LVD? I believe it had a centronics 50 pin connector labeled "differential". I'm wondering what SCSI card I can use with this... Adaptec 2940? Jay

20 years, 4 months

Custom made front panels

by swtpc6800＠comcast.net

When I restored my TV Typewriters I made a metal case. I was looking for a good way to label the back panel. I found an online source for engraved panels. FrontPanelExpress provides free design software (Windows only) and very reasonable prices. www.frontpanelexpress.com I ordered a 4.5 by 13.5 inch panel with punched holes for a DB25 connector, switches and fuseholder. It was anodize aluminum with in-filled lettering. The cost for one was $46 plus shipping. I have a write-up here. http://www.swtpc.com/mholley/CT_1024/Restore/BackPanel.htm Michael Holley www.swtpc.com/mholley

20 years, 4 months

PET startup sequence?? (was LF: Commodore PET schematics, troubleshooting info)

by dwight.elvey＠amd.com

>From: "Dave Dunfield" <dave04a(a)dunfield.com> > ---snip--- > >Any further ideas? Hi Dave It still sounds like a RAM related issue. The 6502's needed to gate the VMA with Phase2 ( as I recall ) to get clean address selects. You might put a scope on this circuit and make sure it looks like it is working well. You should try to create a more exhaustive RAM test. Although, time consuming, GALPAT is just about the most intensive. Dwight > >Regards, >Dave >-- >dave04a (at) Dave Dunfield >dunfield (dot) Firmware development services & tools: www.dunfield.com >com Vintage computing equipment collector. > http://www.parse.com/~ddunfield/museum/index.html > > >

20 years, 4 months

PET startup sequence?? (was LF: Commodore PET schematics, troubleshooting info)

by pete＠dunnington.u-net.com

On Aug 13 2004, 11:27, Dwight K. Elvey wrote: > You should try to create a more exhaustive RAM test. > Although, time consuming, GALPAT is just about the > most intensive. I know Dave doesn't need it now, but a GALPAT is a very slow test for any sizeable amount of RAM. It's also very old, and not 100% effective against certain errors, though much better than some of the common march tests. It was common in the 70s but a fair amount of work on testing has been done since then and there are much better tests now. I had to do a project for a degree course a few years ago, and found a much better test (in Communications of the ACM), which I coded for a Z80. It tests 8KB RAM in less than 6 seconds at 4MHz, but one of its nice features is that it runs in linear time, so 32K would only take 4 times as long (24s) not 16 times as long -- a GALPAT has order O(n^2). During the project, one of my colleagues worked out that the GALPAT he'd coded would take an hour or two for the same memory. It also doesn't need to use any RAM itself on a Z80 (because there are enough registers), though it would on a 6502. If anyone wants a copy I can give you the Z80 code, some notes from the project writeup, and the CACM references. BTW, most modern tests used commercially are less thorough than a GALPAT; they generally depend on the assumption that most faults depend on the bit(s) immediately adjacent to the faulty one, and require knowledge of the cell topography to be properly effective. -- Pete Peter Turnbull Network Manager University of York

20 years, 4 months

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test-drb August 2004