test-drb February 2011

test-drb@ccmp.vtda.org

155 participants
210 discussions

PSU for MicroVAX 3400 Not Faulty But Not Working

by robert.jarratt＠ntlworld.com

A while back I mentioned that I have a MicroVAX 3400 with one of the H7868 PSUs not wanting to work (green light fails to come on). I have just tried the "faulty" PSU in a MicroVAX 3500 and it works just fine. I took a PSU >from the 3500 and put it in the 3400 and it does not work in the 3400 either, only in the 3500. So clearly there is something else that is causing the problem and I am looking for suggestions, especially as the machine is in an awkward location and hard to dismantle speculatively. As a reminder this machine was working fine and I had not done anything at all to it prior to its failure, I had not moved it, changed any components or anything. Regards Rob

15 years, 1 month

Apple Lisa 2/10 - Progress

by terry＠webweavers.co.nz

More progress, I was kindly donated a IWM chip for the Lisa 2/10 by the original seller of these Lisas I have. He extacted it from a Mac 128 board he had lying around. I'm happy to report the machine now boots up. I'm not sure how much further I'm going to be able to take it though. The widget AND the floppy drive both have issues. I feel I might be able to fix the floppy. The widget seems a pretty complicated piece of machinery, info is sparse and I think might be beyond my limited skills. Here is a description of the problem with the widget. The certainly spins and I can hear a definte clack when the break comes off. I can hear drive seeking noises and the light flashes. I then get an "Error 82". From what I can read this is a fairly generic error which just means the internal drive is not working properly. I've tried to install the Lisa Office Suite and Macworks XL 3.0 from floppy. In the former case I'm told there is no suitable hard disk to install on, and the latter throws up an error 96. I've reseated all socketed chips to no avail. It could be a case of just requiring a low-level format, but I can't find anything on the web that suggests anyone actually knows how to do this. The 400k floppy drive has a weird problem. The stepper moves a little on a disk access call but the motor to rotate the disk doesn't go? The disk ejects ok. Things have been cleaned and lubed and I am using DD disks this time. I suspect it might be a sensor problem because once I was examining the drive when the machine was accessing it and tilted the embedded disk up slightly at the front. Suddenly it whirred into life and loaded the disk and the next disk I put in. Then it stopped working again after that. It could be a sensor maybe? Interestingly my other (spare) 400k shows exactly the same problem? However, the drive from my recently fixed Lisa 2 is fine and it was that drive I used to attempt to re-install software on the widget. I'm going to persist with trying to fix the floppy drives. Given that at least one of the drives did work for a short amount of time is hopeful. If nothing comes to light on the widget, I'll either just abandon trying to fix it and be happy with just a working Lisa 2, and/or perhaps simply look at getting one of these: http://cgi.ebay.com/Profile-Widget-Emulator-Board-Apple-Lisa-Apple-III-/140… .It's quite expensive though and I do like to have things original. I'll have to mull on it. Terry ----- Original Message ----- From: "Terry Stewart" <terry at webweavers.co.nz> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Thursday, January 27, 2011 9:10 PM Subject: Apple Lisa 2/10 - Progress > Ok, for those that have been following this project of mine there has been > progress. > > I had a friend visit today who owns a Lisa 2/10. He bought some of his > Lisa ICs with him for swap-out diagnostic purposes. > > The cause of the Lisa 2/10 failing its diagnostic test was indeed one of > the two ICs under suspicion on the I/O board . It was the IWM Apple > 344-0041 (Integrated WOZ machine controller). The other suspect., the > ROM, appears OK (even though it seems a highly unusual version..I should > learn to use my new (unused) ROM burner and take a copy of the ROM for > posterity). > > However, the widget drive itself throws up an error. First things first > though. I'll source a replacement IWM chip first, then worry about the > widget drive. It might just need some exercise. > > My friend also had an IDEFile ProFile drive emulator which we hooked up to > my working Lisa 2. Whoo hoo, it was great to see the Lisa Office Suite > boot into action. It looked very cool and in 1983 it would have looked > even cooler! > > Tez

15 years, 1 month

Using whiteboard cleaner on floppies

by aek＠bitsavers.org

I thought this was an interesting discovery if you're willing to sacrifice the media to recover some data. I've been trying to read some nasty old 360k 5" floppies circa early 80's, the kind that squeek and strip the oxide off in nice little rings. These were probably made from the same nasty stuff they made early 80's magtapes out of. Thinking this might be a dirt/lubrication issue, I tried applying whiteboard cleaner to the disk while still in its sleeve using a lint-free cloth across the slot on both sides, rotate, repeat around the whole disk, and after a few head cleanings was able to recover the data (and the squeeking stops). Weber Costello Markerboard Cleaner (from the label, after water) octylphenoxy polyethoxyethanol trisodium phosphate ethylene glycol monobutyl ether it's probably the glycol acting as a lubricant

15 years, 1 month

Gould electrostatic printer/plotter

by wmaddox＠pacbell.net

The weekend before last, I picked up a Gould 5010 electrostatic printer/plotter along with some PDP8 gear. The technology is interesting. It writes an electrostatic charge directly on the paper, and develops with a liquid toner "fountain" as the paper exits the machine. Mechanically, it's quite simple, with just a single stepper motor to advance the paper and a pump to recirculate the toner. According to some patents I found on the web which appear to match the configuration of the write head, the pins are activated by a clever coincident-current addressing scheme that avoids the need to dedicate a driver to each pin. The product line was eventually bought by Calcomp, which continued to manufacture electrostatic plotters into the 90's. A successor company still provides paper and toner for some models, but the 5010 is not mentioned on the website, and I have no idea whether supplies made for the newer models will work in the 5010. The printer looks reasonably good on the outside. Internally, there are a few rusted places that could use cleaning and repainting, but it doesn't look like it's structurally or functionally compromised in that respect. The vinyl tubing for the toner circulation, on the other hand, has turned brittle and most of it is missing, and it looks like there has been some toner leakage/spillage at some time in the past. Most distressingly, the electrostatic write head is gunked up and/or corroded, and I suspect it is no good. The printer is a free-standing unit, but not particularly heavy. Two guys lifted it into the back of a minivan without difficulty. Before I strip this thing for parts (it has a couple of nice power supplies, among others), is there any interest in it? Does anyone else have such a printer and need parts? --Bill

15 years, 1 month

Debugging a 386 motherboard...

by classiccmp＠philpem.me.uk

Here's one for the PC gurus (I know there are a few of you here!) I've got the 386 motherboard on the bench. It's got four 1MB 32pin SIMMs installed (it can take eight), no graphics card and my POST code display card (which arrived in the post this morning). I've set the jumpers per the manual: http://stason.org/TULARC/pc/motherboards/I/INFORMTECH-INTERNATIONAL-INC-486… The CPU on this thing is an AMD Am386DX-40. The math-coprocessor (Intel 80387DX-33) has been pulled for now. BIOS is an AMI (American Megatrends) BIOS, label on the chip says Copyright 1992. This is the BIOS which has the atrocious magenta-and-cyan setup screen. The POST card is reporting stable power, RESET inactive, and a valid I/O clock. After powering up, I get the following sequence of POST codes cur prev -- -- holds for a second (or so) 02 01 holds for ~15 seconds 06 05 holds for a second 0d 0c holds for a few minutes 00 0d holds forever The POST card has two displays: CUR and PREV, for Current and Previous code. CUR is the code most recently written to the debug port, PREV is the one before that. Now, according to http://www.postcodemaster.com/AMI91.shtml , 0D is "CMOS Shutdown Register Test to be Done Next", and 00 is "Going to Give Control to INT 19H Boot Loader". Does anyone have any clue what these error codes actually mean? Complete guess here, but it looks like the BIOS is having trouble talking to the CMOS RAM chip. Going by the Dallas datasheet, the most likely candidate is that it's writing 01X (i.e. 0,1,something) to the enable bits in CR1, then reading it back to make sure the control register was set up correctly. The readback failed (repeatedly), so it got stuck in a loop. Obviously without a disassembly of the BIOS, it's pretty hard to say for definite that this is the problem... but does what I'm saying sound at least reasonably plausible? I'm thinking my next step should be to plug a couple of Harwin pin headers into the turned-pin socket and probe it with the logic analyser... Does anyone have any other ideas? -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

15 years, 1 month

seeking gutta-percha

by dgriffi＠cs.csubak.edu

I was wondering if someone out there knows how to acquire smallish quantities of gutta-percha for antique-ish fiddling around with. I'm looking for sheets, blocks, or bars of the stuff; not the tiny needles sold by dental suppliers. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

15 years, 1 month

3B1 Unix PC emulator -- keyboard driver (half) done

by classiccmp＠philpem.me.uk

Hi guys, I've just finished adding a rudimentary keyboard handler to my 3B1 emulator (http://www.philpem.me.uk/code/3b1emu). Problem is... it doesn't quite work. I can get into the test software, and if I hit a key it'll drop into the main menu. Problem is, when I get to the main menu, it doesn't seem to recognise the commands I'm entering. That is, I can enter a menu item number (e.g. 6 <CR> for Goto Subsystem Menu), it echoes to screen correctly, but then the screen clears and I'm thrown unceremoniously back to the main menu, instead of getting passed along to the subsystem menu... This happens with all the possible menu selections, and the "expert mode" command ("s4test"). Is anyone aware of any quirks with the test software which might cause this type of behaviour? Does anyone happen to have a 3B1 and an RS232 protocol analyser (or a logic analyser with RS232 decoding)? It'd be really handy to have some dumps of the data sent and received by the 6850 ACIA (the keyboard comms controller chip) when the keyboard is initialised, and when various keys are pressed... (If I had a 3B1 of my own, it'd be on the table downstairs with a keyboard sniffer cable and my HP logic analyser mainframe plugged in...) Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

15 years, 1 month

cctalk Digest, Vol 90, Issue 19 [Subject: Seeking: IBM Coding Forms]

by vintagecoder＠aol.com

Hi Jeff, I have found several on bitsavers.org and maybe one other place. There may be some overlap with what you found but I would be willing to email them to you if you're interested. They're whoppers, about 1M a piece. I guess that is nothing today, but this is my first post and I don't want to start sending attachments to the list. It usually takes right about a week for me to become persona non-grata and I don't want to give anybody an excuse to change the timetable. I don't like change. So the best thing is for you to get them now before I get thrown out of here. I have about 6 different coding forms that I can find at the moment. I could swear I had an RPG coding form but I cannot find it and anyway I've been trying to cut down. I have 3 assembler forms including one in German or Swiss (both Greek to me) and one for System/3. The others are for COBOL and FORTRAN and a weird print layout form for a 150 character width page. I don't know who came up with that abomination since where I come from everybody knows anything past 132 columns isn't worth reading. I am constantly trying to find a way to deal with the huge quantity of archival stuff I have and haven't succeeded until now. There may be more hidden somewhere. I would like to say "Hello" to the list members and thank the list owner for providing the list and the website owner for providing the web site. My background is large IBM systems but I am interested in just about anything that lights up, hums, smokes, or goes bang when you get the wires twisted the wrong way. I am interested in programming languages, usually the older the better although IBM (mainframe) assembler will always be my favorite. At the moment I'm on a retro computing spree trying to learn how to code in DOS assembler. I am having a hard time finding books for that online.

15 years, 1 month

Any recent posts?

by jhfinedp3k＠compsys.to

Is the list active? There were no posts this morning? Please disregard if you see this post. Jerome Fine

15 years, 1 month

New Corvus Mac Disk images...

by curt＠atarimuseum.com

Hi, Okay, well I was told that my original images zipped up on the PC side lost the resource forks and other nuances of the Mac Disks with which they were written to originally... So, I went back to the Powermac, it creaked and moaned a bit due to some battery issues and corrupted HD, after a reinstall of OS 8.1 (7.5.3 just didn't want to cooperate today, though I did finally did take all of the 19 damned disk images and make an Install CD image of it all finally) I got the Mac back up and running... I know, I know... Mac's after OS 7.6 can't read 400K diskettes... WRONG! They can, but with a little help from a wonderful utility I found on macgarden.org called Diskdup + 2.9.2 (the earlier 1.3.2 does NOT work)... Read all of the disks in perfectly, even allows you to save them in its diskdup format or in Apple diskcopy format... So I saved them in both, plus I made SEA images as well just for good measure. Its late, I'm tired, and I need to catch up with some CPLD design work I'm doing, so this wonderful side project was a great diversion for a couple of days, but back to work... I will revisit my Corvus website in a week or so, make the needed clean up and link changes, plus add in some great photo's of a killer Concept setup sent to my by a former Corvus engineer... so I'll be working on the Corvus site more in a week or so... in the meantime: http://www.corvusmuseum.com/software/mac/corvus_mac_disks.sitx Curt

15 years, 1 month

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test-drb February 2011