test-drb December 2015

test-drb@ccmp.vtda.org

191 participants
268 discussions

by ard＠p850ug1.demon.co.uk

I suspect the answer is no, but before I spend a few afternoons tracing out the diagrams, does anyone have a schematic or (real) service manual for the Diablo/Xerox 3000 computer, in particular the MRPRO CPU board. This is a 1980s all-in-one business desktop computer with 2 internal 8" drives. Based on an 8085 CPU. I have one that was mangled in the house-move (the movers decided to cut the keyboard cable for me). I have now repaired that (and the signals do make sense) but I have other faults (these were probably there before the move, I had not run it for many years). Power lines are fine, CPU chip is getting a clock, but the ready pin is held low. So not a lot happening.... The CPU board is not complicated, really (about 50 ICs, all of them standard) so it is going to be possible for me to trace the schematic if that's what is needed... -tony

8 years, 7 months

Precision Instruments PI1200 7 track tape drive, interest anyone?

by mattislind＠gmail.com

We have this Precision Instruments PI1200 7 track tape drive. It can do 200 bpi, 556 bpi and 800 bpi. It should be an incremental type tape drive. Once upon a time (read seventies) it was used for experiments storing PCM audio on tape. But has since then not been used. The manual is somewhere nearby, but I didn't find it immediately. http://i.imgur.com/kYVLN9O.jpg http://i.imgur.com/LsWcLL0.jpg http://i.imgur.com/1LJLKAZ.jpg I guess that someone that need to recover old 7 track tapes might think it can be useful. It is located in Sweden. /Mattis

8 years, 7 months

DEC CPUs, Memory for sale

by useddec＠gmail.com

I have the following for sale from zip 61853. The "L" boards are up to 2 for $10 shipping within USA, 3 for $10 shipping for the "M" boards. For larger quantity, overseas shipments, or other question, please contact me off list. Quantities are limited, and I may have some third party memory i'll look for this weekend. L4000-AA ,KA670 I think, $100 L4001-Bx MS670 32MB $125 L4001-Cx MS670 64MB $200 L4004-Cx MS690 64MB $125 L4004-Dx MS670 128MB $225 M7606 KA630 $75 M7620 KA650 $100 M8637 MSV11 starting at $75 I still have a few RX8-E boards left... Thanks, Paul

8 years, 7 months

Anyone want a copy of DIGITAL ServerWORKS Manager ?

by glen.slick＠gmail.com

Before I chuck these in the recycle bin, does anyone want a copies of DIGITAL ServerWORKS Manager? I have two boxes, QB-4QYAA-SA 3.2 sealed in shrink wrap, and QB-4QYAA-SA 3.3 open box that is slightly crushed. The boxes (at least the still sealed one) look like this eBay item (not mine) listing: http://www.ebay.com/itm/321413114710 The DIGITAL ServerWORKS? Manager Installation and User Guide in the QB-4QYAA-SA 3.3 open box is the ER-4QXAA-UA. G01 version of the ER-4QXAA-UA. H01 manual here: http://manx.classiccmp.org/collections/mds-199909/cd2/network/4qxaauah.pdf It doesn't look like there is a market for these worth the bother of listing them on eBay. Free for the cost of covering postage from Seattle, WA if anyone wants them. -Glen

8 years, 7 months

IBM CMS dumpfile idiocy

by cclist＠sydex.com

Just finished reading a 9 track tape made with IBM CMS in its dumpfile format. Why on earth--or might I say, what idiot--designed this format? First the file data in a series of records, *then* the file name and other metadata. Anyone know of a DOS/Windows/Unix utility to unravel one of these things? I don't feel too much like coding for a single tape. --Chuck

8 years, 7 months

M7859 KY11-LB PROM contents?

by mattislind＠gmail.com

Has anyone dumped the contents of the bipolar PROMs of the M7859, KY11-LB, programmer's console form the 11/34 and 11/04? Dump for both the program PROMS (512x4 4 pieces) and the decoding PROM (32x8 one piece) are sought after. It has a 8008 chip onboard but my logic analyzer trace is not matching very well with the listing in the manual. Maybe the revisions have changed from the manual. And I cannot find the PROM contents in the engineering drawing. /Mattis

8 years, 7 months

IBM Selectric-based Terminals

by pbirkel＠gmail.com

> - intention was to rip all this out and convert it to a full I/O serial terminal, using an Arduino-based setup > that Lawrence Wilkinson has already built and tested: > https://www.flickr.com/photos/ljw/sets/72157632841492802/with/9201494189/ Looks very nice! Is there documentation for it somewhere? I also have a Selectric (unfortunately it's located distant from me at the moment so I can't provide particulars) that I worked on interfacing to a micro in the mid-70's. I was using a MC6800 in my recollection, but I don't believe that I ever achieved operational status. Presumably I was working from an article in one of the hobbyist magazines of the era. I would have guessed Byte, but that doesn't seem to be the case based on recent search. Any hints from folks on what magazine/article that might have been? The Selectric wasn't one of the curvy(ier) office models; I recall it being a rather boxy affair with plenty of right-angles on the housing and a medium shade of blue -- presumably "IBM Blue". Rather utilitarian in design. Even *more* utilitarian than this one: http://www.covingtoninnovations.com/selectric/100112-Selectric-in-situ.jpg It included a full keyboard. I'm not sure anymore whether it operated in local-mode or was set up as two separate devices and therefore needed to be connected up to a remote controller to get local copy. It might have been a rehoused Selectric mechanism in a third-party enclosure and the IBM-like color a red herring. My recollection is that it was longer front-to-back; presumably the rearward extension housed the additional electronics. I have absolutely no idea how I acquired it. No luck finding a matching photo online as yet. I believe that the Selectric came configured for remote operation, but presumably using an EBCDIC-based data stream. I vaguely recall a DB-50 connector, but it's been an awfully long time ... Does this description sound familiar to anyone? ----- paul

8 years, 7 months

Interest level for new PDP-11 indicator panels

by jnc＠mercury.lcs.mit.edu

> I'm trying to get a sense of how much demand there would be for the > indicator panel option (for parts ordering; I have a chance to buy some > discontinued stuff, and I want to know how much to stock up on). If you > would be interested in one or more indicator panels, could you let me > know? (Please don't reply to the list, just to me personally.) I should have mentioned that we'll likely do a UNIBUS version of the card (ENABLE+, and it should be easy to guess why that name :-) as soon as we're done with the QBUS one; the same indicator panels would be supported by both (so they count to the parts pool). So if you have a UNIBUS machine, and would be interested in adding an ENABLE+ _with indicator panels_, I would be interested to hear about those too. Thanks! Noel

8 years, 7 months

Advice and Suggestions for a Debug Feature

by jhfinedp3k＠compsys.to

Sorry for that BAD stuff in the Subject line - my e-mail provider stuffs that in much of the time and I forget to remove it when I reply. If anyone needs a clean copy, I can send it again! Jerome Fine

8 years, 7 months

[SPAM key] - Re: Advice and Suggestions for a Debug Feature

by jhfinedp3k＠compsys.to

>Tapley, Mark wrote: >>On Dec 16, 2015, at 9:22 AM, Jerome H. Fine <jhfinedp3k at compsys.to> wrote: > >>Note that for many CPUs, adding values (a push) results in the >>stack pointer becoming numerically smaller (unsigned of course). >>Internally, the code would handle the actual arithmetic. >> >(Warning: assembly language noob talking, please disregard if I see to be making no sense.) > >1) Does the debugger enhancement trigger a stop on overall size of stack pointer or on cumulative changes? Or could it be selectable (maybe via a negative argument?) > >Here?s what I?m thinking: suppose a routine is expected to remove things from the stack sequentially, then branch at some point to a subroutine. I want the debugger to halt execution when it branches. So I want the stop to occur when the stack pointer first increases, even if it has already decreased several times and its new value (on branching) is lower than where it was when the debug command was issued. > >2) Some machines (6809, which is the only one I?m familiar with) have a rapid-response branching mechanism for real-time control applications (on the 6809 it?s a Fast Interrupt input). Fewer registers are pushed onto the stack so the service routine can execute sooner. Is there a way to handle this situation? Say I expect two levels of subroutine calls, each stacking a full set of registers, but instead I get for the second subroutine a Fast Interrupt and don?t stack enough registers to trigger the debug counter to halt execution. > > Hope this is useful. > > - Mark > Yes, it is useful since it helps to be aware of what other systems do. So thank you. For those of you who might not have known, this is the Y01.16 Symbolic Debugger from RT-11 and in particular the SDHX.SYS variant. From the point of view of interrupts, when stopped at a breakpoint, the complete system is FROZEN - including RT-11 itself which is the operating system that is being used on the PDP-11. As for the user's stack, that is not even a factor since the Symbolic Debugger has its own stack and executes in Kernel mode. In fact, one of the other enhancements was to ass code to monitor the size of the stack for the Symbolic Debugger - which also allowed that stack to decrease. That was especially helpful since the stack must be in Low Memory in order to handle interrupts and subroutine calls. And as for the user's program stack, there is no effect at all. What the Symbolic Debugger does is save all of the user's registers, including the stack pointer of course. The enhanced code would then compare the original value of the Stack Pointer (actually as noted after the current instruction had been executed) with any subsequent value to determine if the conditions had been met to stop the execution of additional instructions, assuming that the value of the Stack Pointer was included (via value2 and / or value3) in the command to execute more instructions. Jerome Fine

8 years, 7 months

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test-drb December 2015