test-drb

test-drb@ccmp.vtda.org

101090 discussions

by COURYHOUSE＠aol.com

now, there is a 11/23 I could love! ---Ed# In a message dated 6/22/2016 9:44:20 P.M. US Mountain Standard Time, glen.slick at gmail.com writes: BACKPLANE", > so the operation is not so mysterious. I had never seen a hex-wide Q-bus > backplane before this. > > There are some pictures of the system and the Q-Bus to 11/40 front panel > interface here: http://www.ricomputermuseum.org/Home/equipment/dec-pdp-1140 >

10 years, 1 month

How do they make Verilog code for unknown ICs?

by swiftgriggs＠gmail.com

In my recent studies of electronics (I'm a noob for all practical purposes) I keep seeing folks refer to Verilog almost as a verb. I read about it in Wikipedia and it sounds pretty interesting. It's basically described as a coding scheme for electronics, similar to programming but with extras like signal strength and propagation included. Hey, cool! Why are folks referring to "Verilogging" and "doing a verilog" on older chips. Is there some way you can stuff an IC into a socket or alligator clip a bunch of tiny leads onto it and then "map" it somehow into Verilog? Is that what folks who write emulators do? Ie.. they exhaustively dump Verilog code for all the chips then figure out how to implement that in some computer programming language like C ? What do folks do for ROM chips and PLCs? I'd think they must dump the code and disassemble it. No? I'm just curious and this is a tough question to answer with Google since I'm pretty clueless and don't know the right words to search for. I notice people talk about correcting their Verilog code, so it must be somewhat of a manual process. I'm just wondering how someone even gets started with a process like that. -Swift

10 years, 1 month

where to find DEC ECO's for KB11-A?

by fritzm＠fritzm.org

Are DEC ECO's available online anywhere? I have not seem them in the usual places e.g. bitsavers... I am particularly interested in ECO's related to the KB11-A (11/45). thanks, --FritzM.

10 years, 1 month

PDP-11/40 modified to be a PDP-11/23

by michael.99.thompson＠gmail.com

On Tue, Jun 21, 2016 at 9:05 PM, Michael Thompson < michael.99.thompson at gmail.com> wrote: > The RICM just picked up a PDP-11/40 chassis that was modified to accept a > PDP-11/23 board set. It also contains a custom board to interface the > PDP-11/23 to the original PDP-11/40 front panel. It is quite an > accomplishment to get the Q-Bus board set working in the Unibus chassis. > I looked at the backplane pictures that I took after the rescue. I assumed that the hex-wide 8-slot backplane in the front of the card cage was the original 11/40 processor backplane. On the back it says "LSI 11 BACKPLANE", so the operation is not so mysterious. I had never seen a hex-wide Q-bus backplane before this. There are some pictures of the system and the Q-Bus to 11/40 front panel interface here: http://www.ricomputermuseum.org/Home/equipment/dec-pdp-1140 -- Michael Thompson

10 years, 1 month

CYBER-171

by bryan＠bceassociates.com

Wondering if anyone out there has such a machine running. It was literally the first computer system I used (at Indiana State University back in the 70's). I had some real fun doing FORTRAN and Pascal programming on that thing. Thanks, Bryan

10 years, 1 month

Programming for the Alto's Mesa

by paul＠mcjones.org

> I just looked in some boxes I haven't opened in decades. I have "Mesa > Language Manual, Version 5.0, April 1979". If the people with the Alto > need this, let me know. It?s been scanned: http://www.bitsavers.org/pdf/xerox/mesa/5.0_1979/documentation/CSL_79-3_Mes… > ... Mesa was a hard-compiled language, but it had concurrency, > monitors, co-routines ("ports", similar to Go channels), strong type > safety, and a sane way to pass arrays around. ... The designers of the concurrency mechanisms (Butler Lampson and Dave Redell) wrote an excellent paper, which can be downloaded from Lampson?s web site: http://research-srv.microsoft.com/en-us/um/people/blampson/23-ProcessesInMe… > Anyone here know or remember Mesa? I'd like to hear more about it. Thanks to the foresight of Al Kossow and others, the Computer History Museum has a repository of Alto source code online, including the Mesa system and some applications such as the Laurel electronic mail client and the Grapevine distributed mail transport and name service. (The repository also includes a lot of BCPL and a small amount of Smalltalk.) The repository is here: http://xeroxalto.computerhistory.org Probably better to start here: http://www.computerhistory.org/atchm/xerox-alto-source-code/ http://xeroxalto.computerhistory.org/xerox_alto_file_system_archive.html Paul McJones

10 years, 1 month

FSOT: 9-slot VME backplane

by dave＠661.org

I have a 9-slot VME backplane for sale or trade. It weighs about 3 pounds when packed. Pictures at https://www.flickr.com/photos/32548582 at N02/albums/72157670027920776 -- David Griffith dave at 661.org 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?

10 years, 1 month

HP Series-80 computers - PRM-85 board case? ... maybe!

by Martin.Hepperle＠dlr.de

Hi, I own PRM-85 boards for my HP-85 and 86 machines. While they are very useful extension modules for these computers, they lack a proper case. I hate to destroy a working interface or memory module just for the case. I read in this list that there are more people interested in such a case. So I designed a replica case for 3D printing, but did not yet try it out. I do not own a 3D printer and the commercial services calculate between $20 to $100 for one shell (upper/lower). This is a bit expensive for some trials, as I expect that the 3D design would need some iterative refinement to obtain a "perfect" case. So: if someone owning a 3D printer and a PRM-85 board is interested in helping me to refine the design by making a test print I could supply the STL files for upper and lower shells. As a "thank-you" I would expect feedback to improve the design. Regards, Martin Martin {.} Hepperle {at} mh-aerotools {dot} de

10 years, 1 month

CDC 6600 emulation - was Re: How do they make Verilog code for unknown ICs?

by jnc＠mercury.lcs.mit.edu

> From: Dwight Kelvey > The RIS[C]/CISC is really not even relevant in todays processors since > the main limiting factor is memory access bandwidth and effective use > of caches. Memory bandwidth has often been the limiting factor over the complete timeline of CPU's/systems. (It would be interesting to draw up a timeline, showing the periods when it was, and was not.) Yes, caches can help a lot, but inevitably they will miss (depending on the application, more or less often). The RISC/CISC thing actually is kind of relevant to this, because RISC focuses on getting the CPU cycles to be as fast as possible, and that kind of implies simpler instructions --> more instructions to get a particular task done. That was part of the motivation for microcoding, back when it was invented; at that point in time, logic was fast, memories were slow, so more complex instructions made better use of memory bandwidth - especially since this was pre-caches. (It also made binary code 'denser', which was important back then, with much smaller memories.) However, more complex instruction sets made the CPU more complicated; microcoding helped deal with that. The 801's breakthrough, at a very high level, was to see the whole system, and try and optimize across the compiler as well as the instruction set, etc, etc. They also realized that people had been going CISCy for so long that people had to some degree forgotten why, and that that assumption needed to be re-examined - especially in light of the then-current logic/memory speed balance, which had shifted towards memory at that particular point in time. Noel

10 years, 1 month

Leaking DEC VR201 monochrome monitor?

by billdegnan＠gmail.com

I picked up a DEC VR201 display today, it was leaking a highly corrosive brown liquid. So corrosive it burned my skin painfully / immediately and I had to wash hands thoroughly. Anyone come across a display that leaked a corrosive liquid like that? The display was stored in its original box, so I don't think the brown liquid was from something stored on top of it, but I don't know for sure. Bill -- @ BillDeg: Web: vintagecomputer.net Twitter: @billdeg <https://twitter.com/billdeg> Youtube: @billdeg <https://www.youtube.com/user/billdeg> Unauthorized Bio <http://www.vintagecomputer.net/readme.cfm>

10 years, 1 month

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