- test-drb@ccmp.vtda.org - classiccmp.org

by cctalk＠ibm51xx.net

Hello All, I've seen references to a CP/M port for the IBM Displaywriter in magazines of the era. Has anyone ever seen this beast in real life? Better yet anyone have a copy of it?

10 years, 1 month

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PDP-11/34a hung bus problem.

by jnc＠mercury.lcs.mit.edu

> From: Don North > If the bootstrap card is an M9312 with the standard console PROM, it > does NOT require any memory to be present/accessible to get to the ODT > prompt that prints out the registers and waits for a command. Ah, right you are; I'm not familiar with the M9312 codes (you seem to have that all well in hand :-), I've only studied the M873 and M9301 codes. But the M9301 'console without testing' code does in fact look like it would run without any memory in the machine. (Which explains some odd features in the code - I'd always wondered about the 'unusual' subroutine caling sequence, but now I see it allows it to work without any memory.) > From: Ed Groenenberg > ISTR that there is a jumper which selects for +12 or +15 volt. Not that I am aware of - see the power circuitry in the drawings, MP-00742, pg. 25. Maybe you're thinking of the M7891 (MS11-L), which does have such a jumper? >> The M7891 uses +/-15V as well as +5V? > Yes, both +5 and +15 is used and measure ok on the backplane. Actually, having looked at the prints, it also uses either -5V or -12V/-15V (there's a jumper). So you might want to figure out i) which your system has (in a BA11-K box, if you have an H745 'brick' you will have -15V, if an H754 -5V; if a BA11-L box, different versions of the H777 provide different voltages, but I'm too lazy to check :-), and ii) check to make sure the - voltage is good too. Although I doubt the - voltage is causing this problem; I'm pretty sure only the memory chips use it, so it's it's not right, probably the memory would return bad data, is all. Noel

10 years, 1 month

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HP41C Peripherals and Accessories?

by nf6x＠nf6x.net

I just became the happy new owner of a nice old HP 41C calculator with a matching barcode wand. I haven't powered it up yet, as there's lots of battery compartment corrosion. I'm looking into getting one of the replacement flex circuit assemblies that have been made for it. I was quite curious about the 41C when I saw them in magazines, but I had never touched one before. My first HP calculator was a 28S, and I finally upgraded to a 48GX a couple of years ago. I think this 41C will be a fun addition to my collection once I get the battery compartment fixed up and get it running. If anybody has any interesting HP 41C peripherals or accessories available for trade, let's talk! eBay and I don't talk any more, so I need to find my new toys the old fashioned way. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

10 years, 1 month

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DEC Correspondent LA12R-06 Ribbons

by tmfdmike＠gmail.com

I bought a few cases of those not all that long ago... Let me see if I can dig up the source. Mike On May 15, 2016 2:38 PM, "Mark J. Blair" <nf6x at nf6x.net> wrote: I think I already know the answer to this ("no"), but is there any remaining source of usable, or at least restorable, ribbons for the DEC Correspondent printing terminal? The re-inking roller in the single ribbon that came with my printer is hard as a rock. Maybe I'll be able to restore the roller or fabricate a new one, but I wouldn't mind having more ribbons on hand in any case. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

10 years, 1 month

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News about hpmuseum.net

by COURYHOUSE＠aol.com

I am glad to see this effort of Jon's remain Independent. I believe he would have wanted it that way. Ed Sharpe archivist for SMECC In a message dated 5/11/2016 11:50:30 P.M. US Mountain Standard Time, curiousmarc3 at gmail.com writes: This is great news despite the sorrow. Thank you for that, the museum is such an awesome resource for HP collectors. I saw your video on the 2116 restoration were both Jon and you appear. We have at least one more at the CHM, just as a static display for now. I hope I can visit you in Melbourne one day. Marc Sent from my iPad > On May 10, 2016, at 2:25 PM, Paul Berger <phb.hfx at gmail.com> wrote: > > The following was posted on hpmuseum.org this morning: > > *RE: Jon Johnston Passes * > As an update to the sad news of Jon Johnston's death, I can advise that the HP museum and the hpmuseum.net website he built will be continued and maintained for the foreseeable future. > > Over the last 8 months I have worked with Jon in restoring items from his collection of equipment and, among a range of items, recently restored an HP2116A computer to working order - one of only two Jon was aware of in the world and the only one that's operational. > > At this stage we have not been able to access the website and put any notices or updates but that should be addressed shortly. > > Jon's wife has asked me to look after the museum and website for the foreseeable future and as much as possible, continue to develop the museum in line with Jon's vision and objectives. > > As a short background, I joined HP Australia in 1982 as a Customer Engineer maintaining HP3000s, HP250s, all peripherals, terminals etc. I stayed with HP for over 26 years (including 5 years in Palo Alto) in a range of Services roles and have many fond memories of the company and the people I worked with. > > While my ability to invest time into the museum is more limited than Jon's, I hope to honour both his memory and the legacy of the 'old HP' by keeping the museum going as best I can, hopefully with help from the HP interest groups across the world. > > David Collins >

10 years, 1 month

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DEC Correspondent LA12R-06 Ribbons

by nf6x＠nf6x.net

I think I already know the answer to this ("no"), but is there any remaining source of usable, or at least restorable, ribbons for the DEC Correspondent printing terminal? The re-inking roller in the single ribbon that came with my printer is hard as a rock. Maybe I'll be able to restore the roller or fabricate a new one, but I wouldn't mind having more ribbons on hand in any case. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

10 years, 1 month

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COSMAC ELF switch panel v2

by spacewar＠gmail.com

I just got the new boards: https://www.flickr.com/photos/22368471 at N04/albums/72157668325096875 Differences of new version: * bezel is black with white legends * legend font is a bit larger and heavier * legends are above switches * switch PCB wiring errors fixed * right angle header * plastic caps installed on all toggles I assembled the new one with C&K switches that are more readily available (e.g., from Digi-Key and Mouser), but I don't like them as much. Originally I used switches with a V-bracket which makes alignment and assembly easier, and they have a uniform threaded bushing height. The more common toggle switches have a longer threaded bushing. This can be seen by comparing the edge-on views; for the more common switches without the V-bracket, the red switch body is seen. I'm soliciting input as to whether the switch legends should be changed from the vector font to a "real" font, and if so, what font and size is desired.

10 years, 1 month

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PDP11 M9301-Yx ROM dumps

by jnc＠mercury.lcs.mit.edu

> From: Rob Doyle > the 'objcopy' utility in the Binutils package can translate between > binary, tekhex, srec, ihex, etc. Right, but the problem is that I had dumps which were what the PDP-11 CPU saw, but due to hardware oddities on the M9301 board, the _ROM contents_ were diferent: bits 1-8 (_not_ 0-7, which would have been simpler :-) have to be inverted. I'm not sure any existing tool could manage that! Speaking of hardware oddities in the M9301, it seems the Tech Manual (EK-M9301-TM-001) has an error: it seems to indicate that the first (low) words in the PROM should contain the first words at 173000 ("address locations 773000 .. are located in the lower 256 words of the PROM", pg. 2-7). However, looking at the prints, the signal "765XXX L" is fed into the high address bit of the PROMs, and looking at how it is generated (Fig. 2-8, pg. 2-8) it should be low when the low addresses (765xxx) are being read, so the low addresses in the PROM should correspond to 765xxx? Also, looking at Mattis' read-out of the actual PROMs, they have the code that's at 773000 at 0x100 in the PROM. So it does seem as if the PROMs aren't organized the way the Tech Manual claims... Noel

10 years, 1 month

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PDP11 M9301-Yx ROM dumps

by jnc＠mercury.lcs.mit.edu

> From: Glen Slick >> No, but I do have a un-annotated dump in octal. Can you point me at ^^^^^ >> a description of Intel HEX format > Or you could just use the SRecord tool package to convert between > binary / Intel hex / Motorala hex I had a look through the doc, but I couldn't find 'octal' anywhere... :-) And anyway, my format is not identical to either Intel or Motorola, so I'd have to write a converter _anyway_, to get from my format to something a tool would understand. (Converting my dumper to emit Intel instead of my format would still mean a lot of work, because I have all these boards dumped in my format - I'd have to swap them all into the machine to get Intel-format dumps.) Plus to which the M9301 ROM format is kind of wierd; the high addresses on the bus (173000 and up) go in the low locations in the ROM, and the low locations (165000 and up) go in the high, _and_ the low bits (0377) of each word (i.e. the two ROMs which hold the low bits) have to be inverted because of a kludge on the M9301 having to do with the way it writes the contents of the switch to the bus when the machine is starting. So all in all, it's just easier to... >> I already have a program to read my octal dump things, so I'll just >> have to tweak that a bit. Which turned out to be pretty easy - probably easier (for me, at least) than understanding the documentation on the SRecord tool page well enough to understand how to make it do what was needed... :-) > From: Pete Turnbull >> Can you point me at a description of Intel HEX format > Take a look at http://www.dunnington.info/public/IntelHEX > There's a description and also some code you could adapt. Thanks for that; alas, by the time I saw it, my brain had turned on and I remembered this wonderful thing called 'Google', which had led me to info about the format! :-) Noel

10 years, 1 month

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PDP-11

by jnc＠mercury.lcs.mit.edu

> From: Dave Wade >> In theory, the M8044-EE should be an "MSV11-DE" (not "MSV11-EE", that >> would be an M8045-EE), but none of my documentation, including the >> M8044 prints, covers such a variant. > The back of the board says M8045 5013128DP1 32K 18bit MOS memory All M8044's I've ever seen say M8045 in the etch. The M8044 is the non-parity version ("MSV11-Dx"), and the M8045 is the parity version ("MSV11-Ex"), and for the M8044's, they just left one row of chips out. >> something like a BDV11 or something > These all seem to have vanished from E-Bay at present. Paul A has (or used to have) a bunch of them. Noel

10 years, 1 month

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Backups

by rodsmallwood52＠btinternet.com

Is it my imagination or do backups not get mentioned these days? Rod Smallwood

10 years, 1 month

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beige rant (was Re: IBM 5150 with red case on ebay)

by jnc＠mercury.lcs.mit.edu

> From: Chuck Guzis > Styles change. And like women's hem-lines, they eventually work their way back to a previous generations' (now semi-forgotten) style. I remember being amused when black became the 'new' 'cool colour' for PC's; back to the era of KA10's and early PDP-11's!! Noel

10 years, 1 month

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11/83 RQDX3 RD-53 Jumpers

by rodsmallwood52＠btinternet.com

Hi Does anybody know the jumper settings on a RD-53 on an 11/83 with an RQDX3 controller and an RX50 Rod

10 years, 1 month

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PDP-11

by jnc＠mercury.lcs.mit.edu

> From: Dave Wade > Cards are > M7264 11/03 processor with 4-Kword MOS RAM > M7940 > M9400ye DLV11 Serial Line Unit (system cosole) REV11-E (240-ohm terminators for Q18) QBUS termination is a complex subject; when you have multiple backplane sections, connected by cables, each section has 'termination'. That's what this REV11-E card is; it's also the QBUS 'out' to the card in the 780 CPU which the console -11 uses to control the /780 CPU. Why it's in the middle slot, I'm not sure (unless things have been moved around)? > M8044ee > m7946 MSV11-?? (My list doesn't contain an '-EE', but it's some sort of small MOS memory, Q18) RXV11 (RX01 8" floppy disk controller) In theory, the M8044-EE should be an "MSV11-DE" (not "MSV11-EE", that would be an M8045-EE), but none of my documentation, including the M8044 prints, covers such a variant. Maybe I need to look in the /780 prints, it may be a special variant for use in the /780 console machines. > M8192 LSI-11/73 CPU; a nice machine, if you can eventually get it running. You'll want a bunch more memory (note that the M8044/8045 cards are Q18, and so you can only have up to 256KB with them - they _WILL NOT WORK_ in a system with more than 256KB in it). > Also have loose grant card.... You mean an M9047? I would start with just the 11/03 CPU and the console card; hook it up to something, and see if you can get it to talk to the console. (Configure the CPU to halt, and fall into Console ODT, on power-on.) It's probably worth getting one of the various LSI-11 CPU handbooks: Microcomputer Handbook (1976-77) Microcomputer Processors (1978-79) Microcomputer Processor Handbook (1979-80) Microcomputers and Memories Handbook (1981) Microcomputers and Memories Handbook (1982) they all cover the quad-width 11/03 CPU. Although they're probably available online, it's very handy to have a hard-copy one; those are available on eBay and such. That backplane is probably a so-called 'serpentine' backplane, i.e. ones in which the (dual) slots are numbered: 1 2 4 3 5 6 8 7 so the console would need to go in '3' if it's the only card other than the CPU (at least, if you want it to be able to do interrupts). Once you get it working in that configuration, you can configure and add the memory card (if you can figure out what the devil it is ;-). And then the RX01 controller. The REV-11 isn't needed in this configuration. The boot PROM for this machine was actually on the card in the /780 CPU, so eventually you'll need a replacement - something like a BDV11 or something (they are available, and not too expensive). > From: Robert Jarratt > The seller said it was indeed out of a 780. Yeah, that's what it looks like. > I got the impression the 11/23 card was just a spare he had that he put > in the enclosure, not really part of the original system. Actually, an 11/73, but yes, definitely not part of the original system. I don't know if it will work in that backplane without the backplane being upgraded from Q18; it might, but that would need some investigation. Noel

10 years, 1 month

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Replacement for a Corcom F2987A EMI Filter

by robert.jarratt＠ntlworld.com

I have two failed Corcom filters in two DEC Rainbows. I see some spares available in the US, but shipping to the UK is likely to be prohibitive and I would like if possible to find a modern equivalent. It is this one: http://meci.com/corcom-12-20129-01-emi-line-filter-model-f2987a.html. I am told it isn't enough to know the current rating (2A at 240V) and that it you need to know the source impedance (and the impedance of the load?). Does anyone know the spec for this filter so that I can get a suitable one? Incidentally, when I fix these PSUs, I may be wanting to pass on one of the Rainbows. In this case it would not be free because I had to pay for it (and drive a fair distance to get it too). The one I may pass on is in a vertical pedestal. I may also have a third one to pass on which has a fault on the system board, I don't have a logic analyser capable of helping me to find the fault though. Thanks Rob

10 years, 1 month

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Tape reader

by jws＠jwsss.com

Does anyone here know how to order this device? It seems to still possibly be offered, but I am not sure how to order it. I'm not sure if the person is on the list, if so you can reply off list. Looked for faq or shopping or buy pointer, didn't find one. thanks JIm http://retropcdesign.com/forums/showthread.php?threadid=6

10 years, 1 month

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Hex file formats (Was: PDP11 M9301-Yx ROM dumps)

by cctalk＠beyondthepale.ie

Pete Turnbull wrote: > On 12/05/2016 22:17, Noel Chiappa wrote: > > > From: Mattis Lind > > > > You don't have a dump of the PROMs in Intel HEX? > > > > No, but I do have a un-annotated dump in octal. Can you point me at a > > description of Intel HEX format, so I can whip up a converter program? (Which > > will also take an array of PDP-11 words, and split it up into the 4 different > > ROM chips, since each word is spread across all 4 chips.) I already have a > > program to read my octal dump things, so I'll just have to tweak that a bit. > > Take a look at http://www.dunnington.info/public/IntelHEX > There's a description and also some code you could adapt. > Does anyone recognise this hex file format from anywhere? #00002110F01140007D6C62B70608&2F #000CED52300119&4A #00113FCB1287ED6A87ED6A10F076&E4 $ As far as I can tell, the first four hex digits is a 16 bit address, followed by up to 48 hex digit pairs of data and the hex digit pair after & is a checksum. The $ appears to be an end of file marker. It came from a Z80 cross assembler which ran on VAX/VMS. Searching for information about it has turned up very little except for a reference on the DECUS website to: V00250 UCAMS: Universal Cross-Assembler for Microprocessors Version: February 1987 however, I don't think this is it. Does anyone have a better description of the file format or anything that might have produced it? Regards, Peter Coghlan

10 years, 1 month

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PDP11 M9301-Yx ROM dumps

by jnc＠mercury.lcs.mit.edu

Re: PDP11 M9301-Yx ROM dumps > From: Mattis Lind > I checked the contents in the machine versus your listing. And now that I think of it, I wonder if the ROM in the board I dumped had any errors? I have two, I should dump the other one and compare - but I forget which one I dumped, and I fried one of them! :-( The board did 'work', but I only used the console emulator, and the serial line loader, so there might be an error elsewhere (e.g. in one of the disk bootstraps). > Two locations have the high bit set for some reason, 165020 read 100501 > and 165032 reads 106303. Well, the second is definitely wrong; not sure about the first, I'd have to figure out what it's doing with that data word. > Trying to run halts the machine with 165102 in the front panel. That's odd, that doesn't make any sense. > Single stepping it it will step to 165106 but become non-responsive > with the lights at 165106. Hmm, does that mean that it actually froze at 165102, or at 165106? (I.e. is the display the address of the current instruction, or the next one?) > I think this is because it had a bus fault. That shouldn't freeze the machine - unless you had a double bus fault (i.e. trying to push and old PS/PC, and the SP is gubbish). Try loading the SP with the address of some working memory before you start the test, and see what happens. You might also deposit 6/0/12/0 in locations 4-12, so that if it does see an illegal instruction or NXM, it will just halt. > So for now, it is not necessary with more disassembly. Unless you have > som spare time of course. Well, I'll keep working on it anyway. > You don't have a dump of the PROMs in Intel HEX? No, but I do have a un-annotated dump in octal. Can you point me at a description of Intel HEX format, so I can whip up a converter program? (Which will also take an array of PDP-11 words, and split it up into the 4 different ROM chips, since each word is spread across all 4 chips.) I already have a program to read my octal dump things, so I'll just have to tweak that a bit. I'm going to need to start blowing ROMs soon (including some sets of 9301-YF PROMs, for the one I zorched), once I get my 29B hooked up, so I might as well start with this... Noel

10 years, 1 month

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PDP-11 (Josh Dersch)

by michael.99.thompson＠gmail.com

> > Date: Wed, 11 May 2016 14:27:49 -0700 > From: Josh Dersch <derschjo at gmail.com> > Subject: Re: PDP-11 > > > The 8{3|5}50s our biggest customer used had Pro380 VAX CONSOLES, I > remember > > our main menu system looked odd on them since they had a bitmapped > display. > > I've still got one of them I think, can't remember the last time I > powered > > it up but I'm pretty sure it was running TSX-11. > > > > While we're on that subject -- > > I have a friend locally with an 8550 that's missing the console Pro-380 > system; if anyone happens to have one (with the appropriate VAX interface > hardware) drop me a line... > > - Josh > Josh, I donated a Pro-380 VAX console to the RCS/RI crew about 15 years ago. They probably still have it. -- Michael Thompson

10 years, 1 month

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PDP11 M9301-Yx ROM dumps

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > I also have a YF card. ... I could access the contents but it didn't > run very well. So either the CPU is still bad or the PROM contents are > bad. Could you please direct me to your YF dumps so I could compare? They are on my "Miscellaneous Digital Equipment Corporation PDP-11 Information" page: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/PDP-11_Stuff.html in the "ROM Dumps" section. > If you also have done a disassembly that would be very interesting. I haven't completely disassembled the -YF version, but the -YA is almost all done, so it should help. Let me know if you need to have the -YF fully disassmbled & commented, and I'll hop to it. Noel

10 years, 1 month

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PDP11 M9301-Yx ROM dumps

by jnc＠mercury.lcs.mit.edu

OK, so we already had a dump of the M9301-YA ROMs, but were (apparently) missing the others? So I fnally got one of my UNIBUS 11's running, and whipped up a small program to dump the ROM contents, and now have the -YB, -YF and -YH ROMs dumped. I'm in the process of disassembling them now. (If anyone needs the contents in binary format, to blow new ROMs, let me know, and I can probably produce them if you give me the details on the format you need the data in.) Does anyone have any of the others - YC, YD, YE and YJ? If you're not up to dumping them, I can send you my small program (currently in .LDA format, but I can convert it to a script - it is not very long at all - for the console emulator in the M9301 series), which will do it - it produces packed octal output, 8 words/line, so a very small output. Noel

10 years, 1 month

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PDP-11

by jnc＠mercury.lcs.mit.edu

> From: Dave Wade > I have recently a PDP-11 which apparently came from a VAX console. If that's really where it came from, it's a QBUS 11/03. (And IIRC only the 780 had a PDP-11 console, although I'm not a VAX expert.) > It looks to me like there are two CPU's in there Well, as Bill said, send us the 'M-numbers' (on the board handles), and we'll tell you what you've got - but multi-CPU PDP11's basically don't exist (with some rare exceptions), and certainly not in a VAX console. So I'm not sure what you have there. > and Bus Terminator Actually, that's the 'QBUS out' connector card; the way the PDP-11 runs the VAX is that there's a card in the 780 CPU which is on the QBUS (there are cables that run from the QBUS out to that card), and it allows the -11 to totally control the 780 CPU. > I have done lots of searching and there doesn't seem to be a simple > list of what can run on it Well, nothing that needs memory management - at least, as it sits. You could swap out the CPU card for an 11/23 or 11/73, then you could run an OS that needs memory management (Unix, or one of the DEC OS's that needs it - I know nothing of the DEC OS's for the -11, someone else here will, though). And your backplane is probably so-called Q18, limited to 256KB of memory, but that's easy to upgrade. Noel

10 years, 1 month

9
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Myths about Lisp [was RE: strangest systems I've sent email from]

by RichA＠LivingComputerMuseum.org

From: ben Sent: Wednesday, May 11, 2016 5:42 PM > On 5/11/2016 5:54 PM, Toby Thain wrote: >> On 2016-05-11 7:43 PM, Liam Proven wrote: >>> If we'd had 4 decades of effort aimed at fast Lisp Machines, I think >>> we'd have them. >> Compiled Lisp, even on generic hardware, is fast. Fast enough, in fact, >> that it obviated Symbolics. (More in Richard P. Gabriel's history of >> Lucid.) See also: The newly open sourced Chez Scheme. > But List still sequential processing as far as I can see? How do you > speed that up? This is another of the long-standing myths perpetuated by people who know nothing about the language. It has literally been decades since lists were the only data structure available in Lisp. If you need non-sequential access to process data, arrays are the ticket, or hashes. Choose the best data structure for to problem at hand. (Similarly, data types other than atoms have been around since the very earliest LISP. They just weren't sexy, and didn't get a lot of press since they weren't novel and difficult to understand. Math code from the MACLISP compiler was better than that generated by the F40 FORTRAN compiler.) >> The myths around garbage collection are also thick, but gc doesn't >> impede efficiency except under conditions of insufficient headroom (long >> documented by research old and new). > Well GC is every Tuesday here. :) You joke, but in one of the visionary papers on GC from the early 70s, a tongue-in-cheek scenario was proposed in which GC was done by a portable system which had sufficient memory would visit large facilities to do background GC for them on, say, a monthly basis. Rich Rich Alderson Vintage Computing Sr. Systems Engineer Living Computer Museum 2245 1st Avenue S Seattle, WA 98134 mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/

10 years, 1 month

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"Retro Repair" key electronics skills?

by ard＠p850ug1.demon.co.uk

> > My father is a civil engineer. When I was a little > kid, he was in the US Air Force. We would frequently > go to the runway snack bar, get ice cream and watch > the B-52s do "touch-and-go" landing practice. The > plane's wings would "flap". It raised the hair on > the back of my neck. My dad explained that, if they > didn't flex, the wings would break off. After a > while, I understood, intellectually. It still "gave > me the willies". Later I had a similar experience > when I was with him in a tall building and realized > that it was "waving in the wind". Same thing, if it > didn't flex, it would fall. That reminds me of the following joke : There is an airline passenger. During some particularly turbulent conditions he looks out the window and sees the plane's wings flexing. He looks very worried. The flight attendant comes over to him and tries to comfort him by saying 'Our pilots are fully trained to fly in conditions like this. It's only turbulence, it's quite normal' He replies 'You don't undertand. I work for Boeing. I am one of the men who designed this aircraft. The wings are not supposed to flex like that.' > > The other is that, as I said before, any ground > > connection has impedance (it's the inductance that > > is troublesome normally) so that points (say IC pins) > > that are shown as grounded may actually have a > > voltage difference between them. > > If I think about it too much, this gives me the > willies, the same way. It's a very real problem, it's the main reason for decoupling capacitors which provide a local source of power with a low impedance connection (as they are so close to the IC). That's why I said that most times the interconnections are the hard part of a digital circuit. -tony

10 years, 1 month

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3D Printing cases and SGI "skins"

by swiftgriggs＠gmail.com

Has anyone used a 3D printer to make a case for their old machine ? I've started drafting an SGI Indy "skin" in Sketch, but it's just a box right now, nothing cool. I've noticed and been somewhat inspired by these: I think this one is very clever. The guy used 3D printed parts just to sort of "glue" the heatsink and lucite/glass together. It looks great. http://technabob.com/blog/2012/12/27/diy-silent-computer/ This guy made one for an Intel NUC: http://tinyurl.com/k9xpb9s This person used plexiglass to overcome print size issues I'm guessing: http://www.ocaholic.ch/modules/news/article.php?storyid=12671 Here is one for a Pi that looks like a NES http://technabob.com/blog/2014/04/27/3d-printed-raspberry-pi-nes-case/ This one is also for a Pi, but is a bit like a laptop, too: http://tinyurl.com/z8rgrmd A C64 custom job: https://3dprint.com/39764/3d-print-commodore-case/ Obviously, this kind of thing would be great for SGIs, which are mostly made to accomidate plastic covers on metal skids (ie.. "skins"). -Swift

10 years, 1 month

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PDP-11

by jnc＠mercury.lcs.mit.edu

> From: Dave Wade > Small card, looks like it fits deep in bus. If it is a QBUS grant continuity card, it will have two looped-back pin pairs (the QBUS has two grant lines - DMA and interrupt) on the back-side, with a blank pin between them. (AM2-AN2 and AR2-AS2, to be exact.) > Any clues on where I can find pin-outs for making a cable. All the DEC 40-pin serial line headers have the same pintout, AFAIK. So you can use any of the manuals for the DL11, e.g. EK-DL11-OP-001, available widely, e.g.: http://vaxhaven.com/images/4/42/EK-DL11-OP-001.pdf which uses that same pinout, and has it in great detail, for making a cable. Those directions produce at DTE cable - if you want to produce a DCE (suitable for plugging into another computer), you need to reverse RD and TD, etc. Noel

10 years, 1 month

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PDP-8/A 128K memory - M8417 or M8418?

by j＠ckrubin.us

I've been looking for a 128K MOS memory board for my PDP-8/A for a while. I finally got one, but it turned out to be an M8418. The docs I've seen (bitsavers EK-MS8CD-TM-001, 1980 + printsets) talk about an M8417 with 4k DRAM chips (MS8-C) and an M8417 with 16k DRAM chips (MS8-D), but apparently at some point the 16k versions became known as the M8418. The card I received has 96 Fujitsu MB8116E 16k DRAMs, arranged in two 8 x 12 chip arrays. The actual circuit board says PDP MOS MEMORY - M8417 - 50 12701B on the back but the metal card ejector edge is stamped M8418 JC. Chip dates on the board put it at 1980 production. None of my literature has the M8418 p/n but most of it may be too old. The M8418 part number (with JC suffix to indicate Fujitsu RAM) does show up in the 1988 Options Module List. I know several list members have similar boards. How are they marked? Can anyone point to more info on the M8418? Thanks, Jack

10 years, 1 month

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Interact Model One Software

by bradhodge75＠gmail.com

Hi guys, I scored a cheap Interact Model One (original with chiclet keys). It's an interesting piece - much larger than photos suggest. It appears to be somewhat functional (comes up to the press L to load tape screen), however I lack any tapes to load with it. I've not found any archives of tapes for this thing anywhere (I guess being an oddball computer like it is, not much demand). Wondered if anyone out there had one of these and if software was out there? Brad

10 years, 1 month

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Bags for RK05 disk cartridges

by j＠ckrubin.us

Now that I've cleaned a stack of RK05 DECpacks, I want to keep them clean. Ideally, I'd like to find Ziploc-style poly bags like the DEC originals with the warning about dirt on the heads (the famous hair/head picture). I haven't been able to find a match for the original (roughly 16.5" square) but I have a sample of U-Line S-14411, a 6 mil reclosable bag that measures 16 x18. It's just slightly snugger than the original but seems to do the job. Does anyone have any other suggestions? Thanks, Jack

10 years, 1 month

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Is there a C compiler for CP/M-80?

by james＠attfield.co.uk

> Date: Wed, 11 May 2016 07:05:52 -0400 > From: Corey Cohen <applecorey at optonline.net> > To: cctalk at classiccmp.org > Subject: Is there a C compiler for CP/M-80? > Message-ID: <F0EEB6C4-53FA-4E58-94FF-9AC3246415CF at optonline.net> > Content-Type: text/plain; charset=utf-8 > > I think the title explains it all. Looking for a C compiler I can run on my Sol-20 > with CP/M 1.4 > > Thanks, > Corey My goto C for CP/M was always BDS C which is I believe still available along with source which is now in the public domain. Comart used to develop system stuff with it in the UK for their S-100 stuff before moving to DeSmet C for 8088/86. There is also Aztec C and HiTech C but I don't have any personal knowledge of them or their current availability. James

10 years, 1 month

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Data General Nova Star Trek

by jws＠jwsss.com

A friend has a large set of paper tape which seems to be from a DG User group (not sure about that, but label on box sort of implies that). The tape pile is fanfold about 10" across in a DG box specially made for such use. We hope to have a reader to digitize it soon, but wonder if anyone knows of such a program? We just have the labels which say that is what the tape has to go on. More photos and the like later. I know that more info would be helpful, but figured I'd ask first. thanks Jim

10 years, 1 month

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Is there a C compiler for CP/M-80?

by applecorey＠optonline.net

I think the title explains it all. Looking for a C compiler I can run on my Sol-20 with CP/M 1.4 Thanks, Corey corey cohen u??o? ???o?

10 years, 1 month

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PDP-11

by dave.g4ugm＠gmail.com

Folks, I have recently a PDP-11 which apparently came from a VAX console. It looks to me like there are two CPU's in there, a console card, RX02 Controller, Memory and Bus Terminator. I have done lots of searching and there doesn't seem to be a simple list of what can run on it, assuming I can find some RX02 floppy disks to go with it.. Any pointers to documentation? Clues on how to arrange the cards in the box. Dave Wade

10 years, 1 month

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Manual for Remex RRJ8000 serial paper tape reader circa 1979?

by nw＠retrocomputingtasmania.com

If anyone knows the dip switch settings, I'd be grateful to learn them please or even better a manual. It doesn't match any of the units currently on bitsavers. Compared to the more common Remex units this one is quite compact. I tried some test tapes and it produces a regular pattern differing only in a couple of bits, I think it is indicating parity errors, I'm guessing one of the dip-switch settings controls parity.

10 years, 1 month

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VT101 screen adjustment

by witchy＠binarydinosaurs.co.uk

Hi folks, Picked up a couple of nice condition VT's today, a VT101 and VT131 though only one DEC keyboard. 2 other keyboards were included which look identical to DEC ones but have different keytops and obvious non-DEC cables though they have the 6mm jack plug on the end. Need to dig into those. Anyhoo, the VT101's screen is showing the stretch-at-top-compress-at-bottom issue, is that adjustable using the troubleshooting guide in the technical reference or am I looking at replacing some caps? I also get character set glitches and it either doesn't register key presses or registers too many, I know it's not the keyboard itself since I've tried my 'DECbox' VT102 keyboard and it does the same. Not looked at the 5V rail yet, that's a job for tomorrow... cheers, -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

10 years, 1 month

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Non-DEC keyboard lookalikes (was: VT1xx stuff)

by witchy＠binarydinosaurs.co.uk

Since I now have a couple of these and google is coming up blank-ish has anyone come across a VT keyboard, possibly from a Plessey PT100 style terminal, that is 99% VT100 in shape, colour and key layout? Even the 6mm jack plug though I know Apple used that too on the Lisa. I found a message thread from here in 2002 about the VT131 and what sounds like an identical keyboard but aside from 'don't knows' and a mention of Plessey nothing else was found and it descended into chat about scanning Microfiche. I toyed briefly with the thought that I'd ended up with the VT and keyboard of those messages but the OP of that was in Champagne IL. Earlier tonight I dismantled one of them in the hope of seeing a manufacturer or any sort of branding but nada. There's a 2716 EPROM marked 'PKB00' which I dumped but there's nothing of note in there either. Maybe the pic will help, maybe not since you'll think 'that's a VT keyboard' :) -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

10 years, 1 month

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Anyone Have a Working AlphaStation 200 to Run Some Tests For Me?

by robert.jarratt＠ntlworld.com

I can?t remember if I already asked, but I need to find a working example and ask it?s owner to run some tests on it for me to help me diagnose a fault on mine. Ideally the machine would be running VMS. Thanks Rob Sent from my Windows 10 phone

10 years, 1 month

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"Retro Repair" key electronics skills?

by elson＠pico-systems.com

On 05/10/2016 02:33 PM, Bill Sudbrink wrote: >> The other is that, as I said before, any ground >> connection has impedance (it's the inductance that >> is troublesome normally) so that points (say IC pins) >> that are shown as grounded may actually have a >> voltage difference between them. > If I think about it too much, this gives me the > willies, the same way. > > I have a 3500 Lb Sheldon lathe. During rebuilding of it, I got a very sensitive electronic level, to aid in making sure the bed was reground straight. I found that when I walked >from one end of the lathe to the other, it tilted about one arc second. That was my weight deflecting the concrete floor of my basement, causing the lathe to tilt slightly. All structures, including the earth, deflect under load. Jon

10 years, 1 month

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"Retro Repair" key electronics skills?

by swiftgriggs＠gmail.com

I figure I'm good for about eighty hours or so of reading and fooling around with electronics before I'll want to move onto a different hobby for a while (I rotate through a whole bunch). That's my normal MO. So, I'm wondering what kind of skills I could build with that time, once I get started. I'd love to hear if anyone has suggestions for how to use my time wisely to learn skills that would be most useful for working on older machines (mid 80's to late 90's is my focus as far as a hardware bandpass). Here's what I (think) I know now: - Basics about electricity. Ie.. Ohms law, power vs frequency, etc.. - I understand basic physics ("A" in 100-level college course and two years of high school physics, too). I actually had an excellent teacher, too! - I used to do math to about a 300-400 level, but now I'm at a 100-200 level (I can still do most algebra II, some trig, and a few other bits). - I understand what most analog components do (resistors, capacitors, diodes, etc..). I can run a volt-meter, and super-basic operations with an analog scope (checking test points and that kind of simple crap) . I also have a rudimentary rig for soldering etc... - Since I'm a coder, I understand boolean logic (which I hope would help with ICs). - I took a digital electronics course in college. However, it was pathetic and it's all gone now anyway. I've spent most of my technical energy learning coding and sysadmin skills, not hardware. I'm still interested in it, though. I'm most comfortable with self-teaching via projects. Any that you folks would recommend (even if they are for kids, I don't mind, I'm not proud) I'd love to hear about them. Books, project kits, etc.. My goal would be able to understand 40% of what is happening on an Amiga 500 or that level of machine. If I could do that.... wow. fun. cool. Plus I bet I could repair many more items/problems than I can today. -Swift

10 years, 1 month

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PDP-8 core memory board

by jnc＠mercury.lcs.mit.edu

FAYI: http://www.ebay.com/itm/262419353233 DEC H219a & G649 8K X 12 Core Memory Stack Noel

10 years, 1 month

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Memodyne M80 Digital Cassette Recorder

by bradhodge75＠gmail.com

Hi there, I have a Memodyne M-80 Digital Cassette 'Computer' which, in talking to people more experienced than me, seems to be just a digital cassette recorder. Googling around there seems to be very little info out there, although one paper written about their use with scientific equipment detailed some of the bits triggered to make the recorder operate. Mine has several cards including a Z80 CPU card and serial input/output. I was wondering if anyone out there was familiar with these and/or had a manual? I read these were even used sometimes with SWTPC terminals/computers, so I'd be interested to see if I can get it running. Thanks!! Brad

10 years, 1 month

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strangest systems I've sent email from

by jnc＠mercury.lcs.mit.edu

> From: Diane Bruce > PL/M wasn't bad either. I forgot about PL/M... > Telephone companies preferred deterministic behaviour from their code > and operating systems. Not just telco's. Many (most?) people doing stand-alone applications want this, or something close to it. > There are many warts in C I would remove if I had the power to. ;) Eh, don't we all. My favourite peeve: in cloning BCPL, they left out 'valof/resultis'. That made certain kinds of macros really, really ugly... > C is a high level PDP-11 assembler to this day. (auto increment and > decrement) This myth persists, but it's wrong. B (the typeless predecessor to C) on the PDP-7 had them, before the PDP-11 existed, as DMR attests: People often guess that they were created to use the auto-increment and auto-decrement address modes provided by the DEC PDP-11 on which C and Unix first became popular. This is historically impossible, since there was no PDP-11 when B was developed. The document that's excerted from: http://www.bell-labs.com/usr/dmr/www/chist.html might be of interest here, since it contains a section ("Whence Success?") containing his take on why C was a success (e.g. "it evidently satisfied a need for a system implementation language efficient enough to displace assembly language, yet sufficiently abstract and fluent to describe algorithms and interactions in a wide variety of environments"). Noel

10 years, 1 month

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strangest systems I've sent email from

by jnc＠mercury.lcs.mit.edu

Oh, another factor that led to success for C, I suspect: I/O is not in the language, it's handled by optional subroutine libraries. This made it very easy for compilers/etc to produce language for stand-alone systems. Compare PL/I, which needed a large subroutine library to run on bare hardware. > From: Paul Koning > Algol 68 has both pointers and structures. Yeah, but Algol-68 never did much (although it had a certain amount of influence). Why, I'm not certain - I suspect the fact that it was fairly complex had something to do with it, but I expect its biggest problem was that a number of _very_ respectd people from its committee denounced it roundly (whether their reasons were good or bad, I can't say). Tony Hoare's Turing lecture, "The Emperor's Old Clothes", recounts a lot of that. (That's the source of the famous quote about "there are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies and the other way is to make it so complicated that there are no obvious deficiencies." He was talking about Algol-68, there.) > So does Pascal. Which didn't have a lot of the capabilities needed to be system language at _that point in time_ (remember, this is about 'why did C succeed, back then'); it was, after all, originally designed as a pedagogical language. > And Modula. That was late 70's - C was already off and running by then. > The main thing C has that most other languages don't is *unsafe* data > typing - the ability to subvert the type system at the drop of a cast, > and the programming tradition to do this a lot. {Sighs.} You really seem to have it out for C. You'll never be able to understand why it was so successful if you start out with the mindset that it's total crap (even if that's not the way you thought you meant that comment). That _is_ the implication of that "the main thing that C has" comment - compared to things available _at the time_, like BCPL, etc, it _did_ have significant advantages. Does it have issues? Sure. But the main reason it was so successful is that compared to the other alternatives available _at the time_, it was, overall, a better mouse-trap. (It wasn't just that it went with Unix - as DMR pointed out, below, it succeeded in a lot of places that Unix didn't.) > But it was cheap, available, and good enough to do useful work. There's a lot of truth to that. Dennis Ritchie's HOPL presentation, "Five Little Languages and How They Grew": http://www.bell-labs.com/usr/dmr/www/hopl.html has a section at the end about "how C succeeded in becoming so widely used", and it's close to that. Some may consider your description a put-down; DMR I expect would embrace it. > I think the answer is simpler: Unix was adopted by a number of academic > groups because it was available on easy terms That certainly didn't hurt, but I don't think it was the biggest factor, by a long way. I think one of the biggest things is that early Unix (I'm thinking V6, V7) was a system with an incredibly high bang/buck ratio - for the size, one got a heck of a lot of functionality. This was important not just for _use_, for for pedagogical reasons - to give students an example of a well-done system. The fact that the hardware it ran on (PDP-11's) was modestly priced (for the day) also helped a lot. > and it was adopted by a very successful company (Sun) Unix had taken off big-time before Sun even appeared. Noel

10 years, 1 month

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It has been quiet.

by kspt.tor＠gmail.com

On 10 May 2016 at 03:12, Eric Christopherson <echristopherson at gmail.com> wrote: > Gmail always tells me COURYHOUSE's messages would have been treated as > spam, if I hadn't specifically exempted the messages of this list from ever > being blocked. I wonder if Google has a prejudice against aol.com > addresses? :) No, it's a problem caused by the mailing list, yahoo (and presumably aol as well) use an authentication system to let recipients validate that the email is legit. That doesn't work properly with many standard mailing lists. Google 'dmarc yahoo mailing list', for example.

10 years, 1 month

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It has been quiet.

by COURYHOUSE＠aol.com

nope it is working In a message dated 4/27/2016 10:48:48 P.M. Mountain Standard Time, dkelvey at hotmail.com writes: Has the list gone down or just dropped me again?

10 years, 1 month

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Memodyne M-80 'Cassette Computer'

by bradhodge75＠gmail.com

Hi guys, I have a Memodyne M80 'Cassette Computer'. From what I've gathered, it's basically just a digital tape drive (it has about 5 boards in it, including a Z80 board with an emprom marked '1200 baud', although from one sales doc it looks like it could have been built out to be a 'general purpose' Z80 computer. I've read these were used for a variety of purposes including SWTPC terminals like mine. What I cannot find though is any actual instruction manuals, etc that explain how to use it. I did find one PDF online as part of a university paper that described another Memodyne's system a little bit. Wondering if anyone has any info out there. It's a neat little box to look at, anyway. Many thanks, esp. to those like Chuck who were able to offer some useful advice thus far on it! :) Brad

10 years, 1 month

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Memodyne M80 'Cassette Computer'

by unclefalter＠yahoo.ca

Hi guys, I have a Memodyne M80 'Cassette Computer'. From what I've gathered, it's basically just a digital tape drive (it has about 5 boards in it, including a Z80 board with an emprom marked '1200 baud', although from one sales doc it looks like it could have been built out to be a 'general purpose' Z80 computer. I've read these were used for a variety of purposes including SWTPC terminals like mine. What I cannot find though is any actual instruction manuals, etc that explain how to use it. I did find one PDF online as part of a university paper that described another Memodyne's system a little bit. Wondering if anyone has any info out there. It's a neat little box to look at, anyway. Many thanks, esp. to those like Chuck who were able to offer some useful advice thus far on it! :) Brad

10 years, 1 month

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Wanted: IA-2000 Z80 CPU board...

by wh.sudbrink＠verizon.net

Hi, I have an InterSystems DPS-1 chassis in pretty good condition coming my way and I'd like to put an IA-2000 CPU in it. Anybody have one they might consider selling? Thanks, Bill S.

10 years, 1 month

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Fw: new message

by julian＠twinax.org

Hello! You have a new message, please read <http://kicnet.de/efficiency.php?6jju> julian at twinax.org

10 years, 1 month

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Calling for [Point 4] IRIS programmers

by microtechdart＠gmail.com

Hi, all. It's been a while since I've discussed anything here. We've made a lot of progress re-constructing a couple of Point 4 machines (as much as one can without the actual hardware), yet still need some help from a few knowledgeable folks in this 35+ year old OS. It was built on the DG Nova foundation, but made by Educational Data Systems, which became Point 4, for their Point 4 machines. So, it doesn't exactly "just run" on SimH Nova. We've been in regular contact with Bruce Ray, who is a true expert in all Data General and related systems. He has already helped us TREMENDOUSLY. http://NovasAreForever.org But other than Bruce Ray, are there any other folks here on this forum who may have had any IRIS programming, either on the Point 4, or another system of similarity in the late '70s to early '80s? I've hunted down a handful of people so far on LinkedIn and scouring the internet, and only a few of those have responded. But I just thought I'd make a shout out here. A small handful have kindly responded, with either limited recollection or availability, or both. In addition to Bruce, those who have contributed so far include David Takle, and one of the original Point 4 IRIS designers, Dan Paymar. We've added a LOT of new content and progress to our restoration/re-creation of what is turning out to be TWO distinct Point 4 IRIS systems. Stop by our site if you like, and especially review the directory page "Understranding IRIS": http://microtechm1.blogspot.com/p/understanding-iris.html Does anyone here have anything to add, or IRIS/Point 4 documentation that could be helpful here (other than what we have at http://microtechm1.blogspot.com/p/manuals.html ). Thanks all, I always appreciate the fantastic feedback here. -AJ http://MightyFrame.com http://MicrotechM1.blogspot.com

10 years, 1 month

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