test-drb

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101090 discussions

by tshoppa＠wmata.com

> 2. How did Humphrey Bogart get in there? > Or is it straight-8 -> treasure -> happy? Suggested language usage: Dude, don't bogart that straight 8! Tim.

16 years, 1 month

They never stop: Yet another fradulent relisting of Ashley's TC11/TU55/RK05 rack

by wmaddox＠pacbell.net

He's at it again: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330411796683&ssPageName=… It's been reported to eBay, as well as to the ebay account owner and the fellow who's website was apparently hijacked to host part of the listing. I've expressed interest in buying the stuff. I wonder if he'll give me enough contact info to get him busted... --Bill

16 years, 1 month

Sorcerer II progress...

by wh.sudbrink＠verizon.net

I rewired the transformer per Pete and Tony (thanks guys!) and replaced all of the electrolytic caps in the power supply. Looking at the Sorcerer One schematics and confirmed on the board, there is a big 10-watt resistor across the +5 regulator like the Altair 680 PS so I tested with the dummy load I made for the 680. All voltages were spot-on. Close examination of the logic board didn't show anything that looked bad so I hooked up a small LCD test display, held my breath and turned it on. I assumed I would get a screen full of garbage if anything, but it turns out the little display can detect and show PAL. The Sorcerer is up 100 percent. The RAM/stack report in the monitor start message indicates that the full 48K is there. I did some random poking around and the RAM looks basically functional. With my luck running this good, I went ahead and powered down and inserted the BASIC "8-track" ROM cartridge. Powered back up and there was Standard BASIC, fully operational. So, it looks like I have a lot less to do with this machine than I thought. I do want to convert the unit back to NTSC and I have not tested the serial or cassette ports though. Anyway, I'm going to do some cosmetics next. The keyboard is filthy, so a disassembly and wash is in order. Next, most of the perforated metal ventilation panels have fallen out. I have them all. It looks like they were glued in place with hot-melt glue. Is that how they were originally attached? Bill

16 years, 1 month

Sorcerer II progress...

by alhartman＠yahoo.com

Rather than drawing a disgram of the keycaps, wouldn't a picture taken by a digital or polaroid camera be easier and faster? Al

16 years, 1 month

HP2631B printer

by ard＠p850ug1.demon.co.uk

You may rememebr that a few weeks ago I asked ofr help on the encoder of an HP2631B printer. I've not sorted it all out, and will describe what I did... The initial problem was a defective 2114 RAM (!) on the procesosr board. After replacign that, the printer rammed the carriage into the side of the mechanmism, blowing the 2 motor driver transistors and an overvoltage zenenr on the -20V line. Furtehr tests showd there were no signals coming >from the shaft encoder on the carriage movement leadscrew. I took the machine apart. Really apart. Not having the special tools to remove the encoder form the leadscrew, I found I could take them out together, You loosen the cap screw in the collar on the carriage motor shafter, free the ribbon cable from the cips onthe rear paper guide, and tkae out the 3 screws from the encoder mounting plate. The whole lot this comes out of the right hand side of the mechamism. I could then remove the end cover from the encoder (carring the IR emitter) and the little cover over the cable connections. The HP service manual warns you not t oremove the carriage rails or platten bar, since 'an important adjustment will be upset'. I reckoned that my pritner was in a pretty bad state already, and little could make it any worde, so I took it all apart. I am wondering what the HP manaul is talking about. The 2 carriage rails have their ends turned down to fit in holes i nthe side plate, so theres no way they can be moved by more than a few thou. And these ends are not eccentric, I checked. The platten bar is locared by dowel pins to each side plate. It can't move either. As far as I can see there is no problem at all with completely stripping the mechanism. This meant I could deal with that substance well-know to all classic computer people -- sound-deadening foam that turns to dust. Back to the enconder. The person who said 'sounds like the IR emitter is out' was vey close. The IR emitter was indeed not glowing. The reason was that it's conencted to the rest of the encoder by 2 little pin sockets on the emeltter assembly (encoder end cover) which fit onto wires coming out of the enocderr boddy -- one of them seems to be the end of a current limiting resistor... Anyway, one of those wires was bent and not connecting to the emitter assembly. Easy to fix when you know where to look! I crelaced the shorted zneer diode on the PSU board, and did some simple checks on the rest of the electronics. The DIP switches on the priner logic PCB and HPIB conenctor PCB were not reliable. Since an HPIB address swithc which doesn't set the address you expect is going to be a curse, I replaced them. I managed to re-stake the puchbutton assemblies on the control panel PCB -- http://www.parts.agilent.com indicates that type of switch (plastic housing heat-staked to a PCB with gold contact pads) is still avaialbe, but only if you return the instrument to Agilent for repair. Sorry, but no way... With everything back together (apart from the motor driver transistors), it was time to give it a go. I could now see that the encoder was producing pulses, that the end sensors worked, and that it wasn't trying to turn on both motor driver transsitors at the same time. Powered down, fitted the (expensive, 25A) motor driver transistors, and tried again with the lesdscrew nut unscrewed from the carriage. The idea was that if the motor 'ran away', it wouldn't slam the carriage into the side plate. Tjhis time on power-up the mtoor ran -- but at a sensible speed, there were plento of pulses from the encoder, and by just touching the leadscrew nut I found it was indeed trying to drive the carriage to the left. Time fore the real test. I ffittd the 3 screws holding the leadscrew nut to the carriage, and tired again. The carriage went to the home position, and the macjhine gave a long beep. The frontpanel buttons did nothing apart from reset (which repeated the initialisation) and On-Line which caused it to beep again. I tried frobbing the paper-out switch, it made no difference, so I guessed I had a real fault. I spend 2 hours looking at signals. The peocessor was clearly running. The end sensor signals were fine. The enocder, position counters, direction flip-flop, and so on all seemed to be doing the right things. I was beginning to think i had a nasty fault in the custom HP procesosr chip. And yet, it was running the firmware, at least enough to run the carriage to the home position, sound the beeper, and so on. Checking what the processor ws trying to do to the pritner logic PCB indicated it was reading the sensors and writng to the carriage motor register, which made sense. It wasn't randoming acccessing all the ports. What had I missed? I went back to the paper out signal. It was high (indicating out-of-paprr) at the input pin of the 3-state buffer on the printer logic PCB. It was low on the motor harness pin on the PSU board (that makes sense, there's a NOT gate on the PSU board which inverts this sigal). But it didn't change state when I frobbed the microswitch. Aha... Although the microswitch is hidden inside the printer mechanism, I managed to disconenct one of the faston terminals from it (the switch is closed when out of paper). This time when I powered the machine up, it homed the carriage and didn't beep. I could do linefeeds and formfeeds >from the panel, the on-line button worked, and the self-test seemed to be trying to print something (I'd not fitted the printhead at this stage. So the microswtich was faulty. Strangely it was stuck closed (most switch porblems cause them to not make contact). I removed the printer mechanism again, turned it over, and removed the rear paper guide (4 screws). 2 mores screws released the microswitch from the guide. And it didn't 'click' when I pressed the actuating lever. Unfortunately, although it's a standard V3 size switch, the actuator is unusual, so getting a replacement would be nnon-trivial. With nothing to lose, I drilled out the rivet holding the swtich together, took off the cover and remvoed the contacts. I then fount that other substance well-known to classic computer types -- grease that turns to cement. Cleaned it off, cleanded thee contacts (well, while I had it apart) and resassmbled it. Now it clicked. And an ohmmeter showet it was woring electrically too. Put it all back together again. Now it will initialise and respond to the control paenl -- provided there's paper in it. Time to fit the printhead (trivial), and it now makes that well-known buzzing that everybody who's ever been near a dot-matrix printer would recognise. Will it print anyhting sensible? Well, let's try the ribbon. Which is jammed. The ribbon cartridge is heat-staked together, but the hold trick of pulling htr ribbon out and widing it back in got it free enough to work. Now the self-test prints a character set -- and it looks quite sensible, Tiem to try it with a computer. I grab my HPIB test set-up (HP71 + HPIL module + HP82169 HPIL-HPIB interface) and cable it all up. Set the printer address to 4 (yes, I used a PET in the old days...) type PRINTER IS 4 and then PRINT. The darn thing does a formfeed (!). Then try PRINT"0123456789". It prints "0000444488" andanotehr formfeed. Clearly the 2 least significat bits (bits 1 and 2 in HPIB terminology) weren't gettign through (an unconnected HPIB line is high, which corresponds to logic 0 on this bus). Hence the CR character was becoming a formfeed... Fortunately I'd picked an HPIB address where this wasn't a problem, I hoped the HP custom PHI HPIB chip hadn't failed. I disconnected the HPIB cabel from the HP82159 and removed the HPIB interface PCB together with the connector PCB and HPIB cable from the printer/And then did continuity checks from the free end of the HPIB cable to the pins on the 3448 buffer chips on the HPIB PCB. Fortuneately bits 1 and 2 were indeed open.And a few morre detaild test showed it was nothing more than dirty contacts on the H{PIB socket. A cotton bud and propn-2-ol cured that. And then it printed properly -- at last. The last job was to fit the cover and platten knob, which was trivial -- at least after everything else. -tony

16 years, 1 month

ISO: Information on Fairchild/Schlumberger EXA 3000

by cclist＠sydex.com

Does anyone out there have information on the disk subsystem of the Fairchild/Schlumberger EXA 3000 tester? I think I've got it figured out, but some validation would come in useful. Thanks, Chuck

16 years, 1 month

HP2631B printer

by Arno_1983＠gmx.de

Rik Bos wrote: (concerning The Adventures of Fabulous Tony with the Dot Matrix Printer): > NICE work ! I'd also like to congratulate to that successful bug hunting and squishing operation and utter my appreciation for its thorough description but... I think that's possible to do without quoting that whole lot ;) So long, Arno -- GMX DSL: Internet, Telefon und Entertainment f?r nur 19,99 EUR/mtl.! http://portal.gmx.net/de/go/dsl02

16 years, 1 month

vintage equip F/S in CA

by shumaker＠att.net

A California Craigs List ad earlier this week caught my eye a couple days ago and some emailing with the seller resulted in the following: ************************************** Bear in mind that Gary was describing things and sometimes I don't get the jargo quite right. OK I have the info that you might like. We have a bunch of Kaypros as mentioned and they are all the same $60 except the 16 which is $125 Kaypro- 2 Kaypro2 - 6 Kaypro4 5 Kaypro10 1 Kaypro 16- in original box with everything Kaypro daisy wheel printer Kaypro pc Heathkit 89 A 2- one with dual floppy , Heath buss, Serial IO card, fan One with single floppy, and a CPU and memory main. We also have one H8 some missing memory chips and much documentation. We are asking $250 for H8 We have a printer buffer as well for that with the manuals, cords etc. Happy to include with it. I took some photos of the bunch of computers in the storage and will send some to you if you wish. However, I have a crummy photo editor and it requires a different email for each photo if I want to send them in a small size. Now, I am planning on listing the H8 in the next couple of weeks on ebay unless someone is serious enough to come up and buy it. We are closing our storage space in the next month or two and really want to see the big computers etc translated into money.. ***************************************************** They added more info today: ***************************************************** As for other stuff, it is a big list, I have over 100 assorted vintage computers (No, no Altairs and only one slightly munched IMSAI front panel). Partial list w/o S-100, Heath, Zenith, Kaypros or Osbornes: 3 each- TI99/4 2 each - TRS-80 Olivetti M15 Apple II Apple IIC Apple IIE Apple Monitor 3 each - Apple Mac (Cube) SE Apple Mac Wyse Video Terminal 2 each - Dual 8" floppy subsystems (Lobo and similar) NEC APC with built in color monitor and dual 8" floppies (seriously cool) NEC APC III with dual 5" floppies and separate color monitor. 2 each - Amiga 500 systems in box SWTPC 6800 Olivetti M-700-10 5 each - Compaq plasma lunch box ASR-33 teletype with paper tape and stand (very clean). Lots of old Monitors. ****************************************************** Units are being sold by a collector who has apprently been collecting since the 2nd West Coat Computer Fair and who is doing some house cleaning They have stated they will put them on Ebay soon but are willing to sell direct to interested collectors... Equipment is physically located in Ft Bragg, CA. contact info is "Barbara McCray" <bamccray at sonic.net> DISCLAIMER: FWIW, I know nothing of the seller or the equipment. She did mention that she sells on Ebay as "Dichroicarts". She is aware that I'm posting this info so if you're interested, go direct! steve

16 years, 1 month

percom data separator

by keithvz＠verizon.net

I've read some passing threads about the percom data separator. Sounds pretty neat. Anyone have schematic, or know the chips involved -- or can tell me how this thing did its job? Thanks Keith

16 years, 1 month

here's one i've never heard of

by brianlanning＠gmail.com

It's Z80 so it's just slightly before my time. But I thought you guys would be interested. It looks really clean. http://cgi.ebay.com/Vintage-Computer-Ibex-Z80-64k-Console-Terminal-RARE-80_… brian

16 years, 1 month

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