test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dogas＠leading.net

-----Original Message----- >I've got Model No. 60-3056. It takes six C cells to run. So that means >that this baby should run off of a 9 volt power supply. > >What should the tip polarity be? I better not get my trusty VOM out and >check that would be too simple. I know what I'll do. I let all the guys >on CLASSICCMP argue about it! Heh...Heh... Why should I do all the work? Ok... hitting the book again: 60-3056. This model is similar to 60-3051 and 60-3054. Refer to section covering 60-3051 to understand the operation of the circutry. Power Supply This model uses the same type used in the 60-3054 except that the zener diode CR1 has been changed from 10% to 5% 60-3054: Power Supply A zener diode is used without the help of a series-pass transistor 60-3051 cannot find tip side polarity though...( or even part # ) for adaptor interesting note from board schematic: The AC Adaptor supplied with the TV game is special type. DO NOT ATTEMPT TO USE ANY OTHER ADAPTOR WITH THIS GAME. It provides 9 volts DC at 225mA... Mike: dogas(a)leading.net

27 years, 10 months

Microfiche Reader/Copier

by jpl15＠netcom.com

Peripherally on-topic... The Company for whom I solve the Equation: (1) Time[mine] = Money[theirs] is consolidating and cleaning up our mess of a warehouse. I have already rescued a bunch of HP 3000-series and a uVax II.. I have got some mid-80s IBM mini stuff coming, and a neat Voice Mailbox system.. more info when I get it home. Existing (and slated for the Evil Dumpster) is one, maybe two, Canon microfiche reader-printer thingys.... any interest among us on the List? They are kinda big (tabletop size), condition unk, been sitting in the warehouse for ten years probably, but the price will be 'You ship it, it's yours'. I know some of you have extensive fiche docs... Speak up rather soon (this or next week) and I'll get more info and poke into them further.. can also take/e-mail pics.... Let me know. Cheers John

27 years, 10 months

rd54s

by allisonp＠world.std.com

< Here's a question. I know there used to be SCSI boards for microvax IIs < can you boot from those? If so, wouldn't it be better in the long run t Most of them, yes. I'm using a CMD board and it boots just fine. There is a disk size limit for the boot disk on some machines if its over 1gig. The problem is SCSI cards are not cheap even used. < I know there's no "right" answer, but I'm curious what folk think. To me a Microvax with a SCSI card is not an abomination. This would be especially true if you used a RZ55 or 56! Now if you put a SCSI on a 780, that would be a hack. However, it would allow the use of the CPU with a less power hungry disk. Allison

27 years, 10 months

rd54s

by allisonp＠world.std.com

< Well, I found a place that supposedly is still selling RD54s, plus a ton < other stuff for old DEC machines. (they want $200 for an RD54). they are out of their minds! that price would have been considered too high 5 years ago. RD54 is a MFM drive, MAXTOR 2190 series. No majik. Allison

27 years, 10 months

Teac fd problem, uPD77C25 data sheet/book & 30-pin SIMMs

by allisonp＠world.std.com

< The NEC uPD77C25 is some kind of DSP chip. I'm trying to find a data she < data book for this. No luck on searching the NEC web site. Does anyone k < where I can get this? < Likely you can't. It is a single chip 16 bit fixed point DSP DSP with ROM code and the code is specified by the engineer that designed the product it's in. The part is available as mask rom, OTP eprom and UVeprom. A data sheet will help ypu understand the part but will tell you little of it's programming in for whatever product it was in. Allison

27 years, 10 months

Outlandish mainframe rescues wanted

by CLASSICCMP＠trailing-edge.com

>I don't remember the exact order of events any more as to which came first, >but I think the first thing that happened was that UW Protection and >Security, as they were then named, did manage to notice us, and a woman >officer questioned us. We explained the arrangement, and she took down our >identities, but, somewhat understandably, wanted further proof of the >arrangement. Heh. When I was at Caltech, the director of my lab gave the security folk strict orders that I was not allowed to bring any of my junk *into* the lab on weekends :-). Tim.

27 years, 10 months

Radio Shack TV Scoreboard

by dogas＠leading.net

From: Sam Ismail <dastar(a)ncal.verio.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Subject: Re: Radio Shack TV Scoreboard >I just picked one up recently and you're in luck: it has an internal power >supply, so all you do is connect a two-prong electrical cord to it. Hi Sam, you must have the 3055 or 3056 model... I've now got service guides on these and other models. - Mike: dogas(a)leading.net

27 years, 10 months

My MVII is not working

by cfandt＠netsync.net

Hey MVII gurus! Along with working on my uPDP this morning I tried to get the MVII running. Well, the negative things folks have said about RD53's are definitely true. It would not spinup properly. Seemed to have a speed control problem as I could hear the drive electronics alternately whine and be quiet in rather frequent, constant intervals even after some lengthy period of time. It's shot I guess. Let's go through what transpires after either power turn-on or hitting 'Restart' as I wrote it down from the screen: KA630-A.V1.3 Performing normal system tests 7..6..etc. <this section passes okay> Tests completed Loading system software. 2.. <more than a minute wait here> ?54 RETRY 2.. <another wait> ?54 RETRY ad infinitum or at least untils the cows come home . . . <I turn off power here and give up> So, what we learned here is that the KA630 ROM is version 1.3 and the failure error is 54. What exactly does '54' mean (I have no tech manuals or anything for this machine to help here)? The inside of the TK50 is rather dusty and dirty. I plan to take it out and get as much dust and junk out of it as possible before I put in a tape (I got the DEC MVII Diagnostic tape, MicroVMS 4.2 and a DECUS tape with a bunch of utilities :) ). How critical is it to have a very clean drive? Seems the opening on the front of the drive with no tape inserted allows too much junk to wander into it. Anybody have an RD54 or equivalent they're willing to sell me? Thanks for your help again, Chris -- -- Christian Fandt, Electronic/Electrical Historian Jamestown, NY USA cfandt(a)netsync.net Member of Antique Wireless Association URL: http://www.ggw.org/freenet/a/awa/

27 years, 10 months

Teac fd problem, uPD77C25 data sheet/book & 30-pin SIMMs

by mark_k＠iname.com

Hi, Several things in this message. A 3.5" HD floppy drive in my old PC, Teac model FD-235HF, is showing a fault which I hope is easily fixable. Here are the details: - Normally when you insert a floppy disk, the drive motor spins until the spindle engages with the rectangular hole in the metal hub of the disk. - This does not happen with the faulty drive. Well very occasionally it does, so I guess the problem may be intermittent. Since the spindle is not engaged, trying to read a file or get a dir listing fails -- the motor does not turn at all when I try to do this. - If I manually turn the drive flywheel(?) slightly after inserting a disk, the motor does kick in and spins to engage the hub of the floppy disk. It's then possible to access the disk as normal. - The fault is definitely with the drive and not the computer's floppy controller (verified by swapping with a different FD-235HF drive). Any ideas? The NEC uPD77C25 is some kind of DSP chip. I'm trying to find a data sheet or data book for this. No luck on searching the NEC web site. Does anyone know where I can get this? If anyone (preferably in the UK) has some old 30-pin 1MB or 4MB SIMMs that they no longer need, please contact me since I could do with at least 2MB worth. I'm also looking for a 16MHz 387SX chip. Bye, -- Mark

27 years, 10 months

Posted tonight

by DaveyGF＠aol.com

Could you detail how the issues of the Altair notes are sequenced? How many volumes? what years? how many issues per volume? When did they start? When did they stop? Thanks, David p.s. even if you don't have them all, if you know the answers to the above questions that would be good enough.

27 years, 10 months

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