test-drb September 2015

test-drb@ccmp.vtda.org

198 participants
312 discussions

by gerardcjat＠free.fr

That triggers again a question I had for a while ... HOW OFTEN theses old PROM fail ?? Who had been through this problem and does it "really" worth to have some blanks "just in case" ?? --- L'absence de virus dans ce courrier ?lectronique a ?t? v?rifi?e par le logiciel antivirus Avast. https://www.avast.com/antivirus

8 years, 10 months

Control Data 160

by jnc＠mercury.lcs.mit.edu

> From: Mark Linimon > excellent post. Ditto. Thanks for sharing those memories, and history, with us, Mr. Pettit! Noel

8 years, 10 months

Even more PDP-8/A weirdness (was: Re: PDP-8 diagnostics SR settings?)

by charlesmorris800＠centurytel.net

As previously posted, reseating the boot ROMs in their sockets cured the corrupted boot loader issue. Got lucky there :) In my system there are two RL02 drives. I will call them "Top" and "Bottom" here, after their physical locations. I put the OS/8 pack that had been acting strangely in the bottom drive (faulting the disk and halting the 8/A when OS/8 was interrupted with Ctrl-C) in the top drive, and switched unit plugs. It works perfectly there! Ctrl-C returns to the "." prompt as expected. The pack I formatted also still reads four 4000+ blocks partitions when switched to the bottom drive. As before, the AJRLHA diagnostic (Seek/Fctn) still faults and prints errors, but only at the start of testing the drive. Thereafter that drive shows no errors. Then the program will switch to the other drive and the same problem occurs. Specifically (edited and reformatted for clarity, with results interpreted from the RL02 user manual): (Ready light goes out, Fault light on) STATE NOT 5 AFTER SEEK WITH 0 DIFFERENCE (this error and register dump prints twice in succession. State 5 = Lock-on, keeping on track). WD1 0317 (lower head, heads not out, spin-down) WD2 0204 (write data error, write gate error). This one worries me. WDE is "write gate on but no transitions on write data line". The drive should never be trying to write when there is no data being sent, and this diagnostic program does not do any writes to disk! So a fault, head retraction and shutdown is the proper response to this fatal error. I'll have to put a logic analyzer on the appropriate bits and see why it thinks it's supposed to be writing... or where the command came from. ERROR FLAG SET ER 2000 (Operation incomplete within 200 ms). Probably because the drive shut down when the WDE error occurred. CB 0003 (Seek) (Fault light goes out) ER NOT AS EXPECTED BUT ERROR FLAG NOT SET (prints this block twice) WD1 0235 (heads out, lock-on, keeping on track) WD2 0002 (Volume check bit, no errors) ER 0003 (Drive Error and Drive Ready) CB 1004 (8-bit mode, Read Header) BAD STATUS RECEIVED FROM DRIVE (also prints this block twice) WD1 ACTUAL 0235 (heads out, lock-on, keeping on track) WD2 ACTUAL 0002 (volume check bit) WD1 EXPECTED 0234 (heads out, seek - track counting) WD2 EXPECTED 0000 (no errors) Some of these errors look like a "cascade"... because the first false-write error occurred, the others are flagged before the drive can become ready again. Then it goes on to run for about 10 mins, flickering the Ready light constantly so it's very dim, obviously accessing as fast as it can. No further errors. Next the program switches to drive 1 and the results are identical, except the "STATE NOT 5" message has WD1 0217 (upper head, heads not out, spin-down). So only the Seek diagnostic is giving errors... the AJRLIA diagnostic (Read/Write) and 'KA (Performance Exerciser) do not show errors. Writes the entire pack and reads it with no errors. I suspect it has automatic error retry but without the source code, that is speculation. Anyhow it may be time to break out the scope and RL02 service manual and check some settings and waveforms... But I still think this is actually a problem with the RL8A controller and not *both* RL02's, since both drives return the same errors, and never had problems like this before... Any help making sense of this mishmash of errors would be greatly appreciated :) -Charles

8 years, 10 months

punchcard svg file available

by gerardcjat＠free.fr

@ simski, who wrote : >Hi, > Hmm. russian carsds. sounds interesting. I'm certainly interested in > their looks. could you post a scan of one of them? Well, they very much look ( and feel ) like original IBM ones, with : - Right angles : NO rounded corners - Characters printed : standard 0 to 9 row numbers with 1 to 80 column numbers over "0" ligne and "9" ligne - only two cyrilic "labels" (??) printed sideway at the leading and trailing edge of the card. Color is what ** I ** call light brown, but there is certainly a more accurate word for it, something like "bistre" ?? All the prints are printed quite "light" and I am not sure it will go through scan correctly (!!) . I will try next week ( scanner un-connected right now ;-) ) If interested ( as collector's item ?? ) , I may send a couple. PM me. --- L'absence de virus dans ce courrier ?lectronique a ?t? v?rifi?e par le logiciel antivirus Avast. https://www.avast.com/antivirus

8 years, 10 months

Control Data 160

by bpettitx＠comcast.net

"wmachacek" <wmachacek at q.com>wrote: Subject: Control Data 160 I have a CDC "160 Computer Programming Manual" that I obtained many years ago when I was working with CDC equipment. This manual caught my eye and I squirreled it away since we were using the 160-A computers not the 160s. This manual has a publication number of 023a and a date of 1960. The picture shown inside the manual is pretty much like the one described herein. It shows the dropped side panels. The manual shows the Ferranti paper tape reader and the BRPE paper tape punch as standard equipment. As optional equipment it shows Ampex magnetic tape handlers (FR300 or FR400), an 80 column punched card reader (no maker listed), an 80 column card punch (no maker listed), a line printer (no maker listed), a Soroban-modified IBM electric typewriter, and a digital communications line buffer. This manual has 45 pages and shows a full view of the computer and a close-up of the front panel. I always kept this as a kind of a CDC oddity as I had heard that the 160s were a proto type and never actually went into production. At least that is what I heard back then. I hope this information kind of helps to better identify these computers. Bill ............................................... Bill, I have a copy of that manual here and was just looking at it. I believe I have all of the 160 and 160-A documentation and software. I have been giving it all to Al Kossaw to add to bitsavers. He is overloaded with so much that needs scanning, that it may be a while before getting posted. The early 160's used IBM punched card equipment. The 088 was the usual card reader of choice. Punching was via an IBM 523 or 521.. Printing was on a 1402 or 407. All these devices used an adaptor called the 1610. Later, printing shifted to the Analex 1000 lpn drum printer. Horrible machine to work on. A cheaper printer also became available: the 501 drum printer. It was made by Holley Carburator! I think it was their only venture into computerdom. Very unreliable machine, used Teflon hammer assemblies. I never saw a straight line of printing on any of those machines. Much of my early career at CDC was swapping out the foreign peripherals and replacing them with CDC ones. Including the Ferranti Paper Tape Reader. I'm a little hurt that the 160 is thought to never have gone into production. I was a customer engineer in the Twin Cities area and worked on lots of them, including some that went to NCR. Even Honeywell used them to test production .transducers. This was the first 12 bit machine, and went into production in 1958. It was extremely reliable. Other than paper tape gear and typewriter repairs, the only failures I can remember are burned out light bulbs and push button switches. Its main signifigance was the development of processing the peripheral operations so the large mainframes were freed up for the big jobs. That lead to the 6600, 7600 and the Cyber Series of computers. Even today, I/O is staged so the big processors are freed up. The 160 was a Seymor Cray design. The 160-A was designed by James Pederson in the early 1960's. It was at the request of several customers who needed more peripheral processing power in the fledling space industry. Most of the early 160-A sales were to the aerospace industry. I first worked on them while in the Army. They were used on missile engine test fixtures in Humtsville, Alabama. Incredibly reliable machines. My personal machine (s/n 190) is still working, complete with all origianl parts. Made in 1963. 52 yers old and still chugging along. Sadly, I had to give it up for health reasons. It's now on its way to a Museum. Billy Pettit

8 years, 10 months

Tandy CoCo Joystick Adapter

by iridius＠yahoo.com

Greetings cctalk list .. I'm about to do a one time run of some CoCo 3 Joystick adapter PCB's. Using this simple PCB, along with one IC, 8 resistors, some wire and the two connectors, an adapter can be built to adapt an Atari style 9 pin Joystick to a CoCo 6 pin DIN, allowing one to use a digital joystick with their Tandy Color Computer. More info at .. http://www.lemon64.com/forum/viewtopic.php?t=57859

8 years, 10 months

C-64 / Epyx FastLoad bug(s)? Workaround?

by drlegendre＠gmail.com

Anyone here using (or have used) a C-64 with the venerable Epyx FastLoad cartridge? I'm running into a VERY annoying bug, and would like to know what if anything is known about it. Bug works like this.. Use the FL "$" command to display the disk directory. Immediately after, try to save a program to disk that has a certain number of chars in the filename in common with another filename on the disk. For instance [SAVE "PROGRAM03",8] when a file (or files) named "PROGRAM01", 'PROGRAM02", etc. already exist. The bug results in a 74 "drive not ready" error, and the save fails. Sometimes picking a more unique filename will allow a save. Other times, it seems no filename will allow a save. Only way I've found to get around the error is to load a different file.. which is no good, as it will overwrite the one in memory. So far, I've only noted the bug when working with BASIC files. What's up with this? Is there a workaround?

8 years, 10 months

WTB: Teletype parts

by drlegendre＠gmail.com

Need the following items for an ex-Bell System Model 15 TTY: Keycaps - F K L C V B N with punctuation symbols, rather than fractions. I have a set with fractions to sell or swap. Keycaps - CARR RET and NULL (blank). These are missing. Platen crank - This is missing. Think that's all for now. I put out a word on Greenkeys but haven't had any luck, though I'd try the ever-helpful classicmp list! Please contact off-list where appropriate. Thank you!

8 years, 10 months

Even more PDP-8/A weirdness (was: Re: PDP-8 diagnostics SR settings?)

by charlesmorris800＠centurytel.net

Update: The first thing I tried was removing and reseating the boot ROMs (465A2/469A2), since they did not use good machine-tooled sockets. Now the boot loader performs normally, no incorrect locations, and OS/8 boots from Drive 0 whether using the boot key or manual start at 0001. Great! So of course, ANOTHER new problem shows up... OS/8 boots and runs, will run PFOCAL, BASIC, give directory listings... But when I hit a Ctrl-C (for example, during a directory listing), Drive 0 Ready goes out, the Fault lamp lights and OS/8 halts. The last instruction showing on the display is 07605, 6213 (CDF CIF 1). I can hit the boot key and as soon as the drive becomes ready again, presumably relocating track 0, the system boots back to the "." prompt. The DF/IF logic is on the same Option 2 board with the bootstrap and auto-restart circuitry. Maybe there's yet another bad connection I have now disturbed... Time to start running diagnostics again! I am really feeling like I'm on a snipe hunt here... sigh. This system was working for many years up until about 2 years ago, then it all went to pot.

8 years, 10 months

bendix GE-15?

by w2hx＠w2hx.com

I think someone on one of the lists was inquring about this. Some items that might be of interest http://www.ebay.com/itm/Rare-Vintage-Bendix-G-15-Mainframe-Computer-Circuit… http://www.ebay.com/itm/Rare-Vintage-Bendix-G-15-Mainframe-Computer-DA-1-In… and a bunch of magazine advertisements Eugene

8 years, 10 months

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test-drb September 2015