test-drb September 2015

test-drb@ccmp.vtda.org

198 participants
312 discussions

would like to find blue dg et head looking terminal to go with small ecli...

by COURYHOUSE＠aol.com

One thing first look at this and need more info on it and docs. wish I had more info on this IBM tube type digital logic trainer kit. comes in a wonderful fitted case with all kinds of plugable units see url http://www.smecc.org/wpe_files/wpe45.jpg current project 3000/37 and micro 3000 Looking for more 3000 stuff both small and large ( cx, ser I,I ser III etc.) Pulled them all over to the media center where I could spread out and work on them. ok here is some of our stuff. we are not exclusively a computer museum but we do have some <grin!> Other areas are scientific instruments, radar and radar countermeasures adn other electronic warefare radio and TV broadcasting, Rural Electrification, Tools of the journalist, office automation 1800's forward. Telecommunications for the Deaf and Hard of Hearing and on and on Some Minis H 11 ( LSI-11 by DEC but in Heath packaging ) DEC PDP8 classsic sn/18 HP-2116b HP-2000 access system (has 2 2100 in it) HP3000/37 ( when it is in the building) eclipse s20 need to clean and wedge in Dec PDP 11/20 DEC PDP-8 S NEXT cube, printer, monitor and all next-y related chachakies who know what are in the other buildings Micros... Intel Intellect 8 Altairs Imsais many Comidore things many R.S. Heath h-8 Heath H-89 several osbornes apples sun-sparc lots of single board computers cobalt cube next cube with all accs a bunch of other ss many many hp desktops and pcs love the prtototype iHP Integral we have too trainers and digital labs IBM really early with tube type plugable units DEC lab Fabritec lab wish I had more info on this IBM comes in a wonderful fitted case with all kinds of plugable units see url http://www.smecc.org/wpe_files/wpe45.jpg In a message dated 9/22/2015 3:25:29 P.M. US Mountain Standard Time, jwest at classiccmp.org writes: Awesome. What minicomputer systems do you have on public display besides the DG? I'm glad to see more DG representation of course :) ---- This month's 'make computer work ' project is HP-3000 related. ---- I'm a bit of an HP fan ;) What's cooking 3K-related?

10 years

Core memory and OS/8

by charlesmorris800＠centurytel.net

<EmilyLitella> Never Mind! </EmilyLitella> I put the 32K SRAM board back in with the top four fields disabled. Sure enough, OS/8 booted and MEM showed 16K, which confirms my recollection that it will work with less than 32K. Then my lights came on - I had made an elementary error... I had selected the wrong MM8-AB 16K core board, the one that was jumpered for field 4-7. So there wasn't any core in fields 0-3 which will "break" OS/8. When I fired up the system with only the board jumpered for the LOW 16K core, everything works as usual. Sorry for the bandwidth... -Charles

10 years

Are we different?

by c.murray.mccullough＠gmail.com

I was reading an article in Maximum PC, Nov. 2015, p.82 that got my attention. It said: ?When the lower orders knew their place?? I wonder if he means users of vintage computers? Just asking! Happy computing. Murray :)

10 years

Core memory and OS/8

by charlesmorris800＠centurytel.net

One of the reasons I bought Vince's 32K SRAM board for my 8/A is because I was having flakiness with my "real" core boards (two 16K and one 8K). Now that OS/8 is running again, and my RL8A and two RL02's are as debugged as they're going to get, I decided to experiment with the old core. Put them back in the chassis and... the two 16K boards are now working perfectly. I ran it for two long passes with DHKMAD (checkerboard diagnostic) with no errors! What's strange, though, is that OS/8 won't boot unless both 16K boards are in the backplane. Then it does boot and a MEM shows "32K MEMORY!" as expected. Won't boot with 16K or 24K of boards, either. I thought that only 12K was mandatory (at least that's what the Device Extensions manual says for an RL01). Or is that something that's set up during BUILD?... I don't see anything in the OS/8 manual and I know I had OS/8 running with 16K and 24K previously. -Charles

10 years

Query for dec teleprinter roms

by jgevaryahu＠gmail.com

Does anyone have an LA36, LA120 or LAS12, LA34, LA100, or LA210 somewhere which they could dump the ROMs from? Notes: The LA36 uses several proms for its discrete cpu, and 2 character set roms which I believe have an 'odd' pinout. The LA120, one of the roms on the '2 rom version' is an 8k 2364 24 pin chip which is a bit annoying to dump, since you either need a 2364->2764 24->28 pin adapter, or (better) a programmer which can dump MC68764 or MC68766 24-pin 8k eproms (which have the same pinout as 2364). The other rom on the 2 rom version is a 2k 2316 24 pin chip. The oldest LA120 version uses 5 roms, all 2k 2316s. The code on the 5-rom version and the 2-rom version may very well be the same (the first 4 2k chips consolidated to one 8k chip), I'm not sure. Would be nice to get dumps of both versions. The LAS12 uses different code from the LA120 and to the best of my knowledge all LAS12s use 2 roms, one 8k and one 2k. LA34, theres at LEAST five firmware versions, almost certainly six, and possibly as many as seven. There is also a special firmware for a 'rom expansion' daughterboard. The 1978 LA34 "54-13374" motherboard has a bizarre Intel i8355 mask rom+io chip in it, plus a separate rom as well. (there are at least two versions of said i8355+rom firmware). Dumping the i8355 is not for the faint of heart, it would likely be easier to insert a 'dumping program' eprom into the single rom's socket, and use the LA34's cpu to spit its own rom contents out via serial. The 1980 LA34 "54-13747" motherboard lacks the i8355 and uses 2 or 3 mask roms or eproms on it instead (and 74xx logic for the i/o). There are at least three rom revisions for this, possibly four or five. LA100 (AKA LW100)... I have no idea. There's definitely at least one rom revision. Also to the best of my knowledge neither the maintenance print set nor the technical manual for the LA100 are scanned (they certainly don't appear at http://bitsavers.trailing-edge.com/pdf/dec/terminal/la100/ ), which makes it difficult to know. -- Jonathan Gevaryahu jgevaryahu at gmail.com jgevaryahu at hotmail.com

10 years

Structured Fortran - was Re: Self modifying code, lambda calculus

by rickb＠bensene.com

Chuck wrote: > > For those wondering about the notion of an "optimizing" assembler, one > has to realize that 650 instructions were executed from a drum and were of > the "1+1" addressing type. Calculating the optimal address of the next > instruction was very tedious and a perfect task for automatic optimization. > Many moons ago I did some programming on a process control computer made by 3M. The machine was a 24-bit word, bit-serial, transistorized machine with drum as main memory. Each instruction contained both the operand address and the next instruction address (in block/track/sector numbers). Depending on the timing of the instruction, the optimal address for the operand and next instruction were calculated based on offsets given in the instruction set summary. There were no index registers on this machine, only a single accumulator register (implemented as a shift-register). The only way you could do table operations or jumps based on evaluation of an expression was self-modifying code. However, this was tricky, if you wanted the code to run as efficiently as possible (minimizing waiting for rotation of the drum), you had to do optimization calculations as part of the self-modifying code. The other tricky part was the you had to be aware of track and sector numbers and properly deal with overflowing, e.g., max sector number was , IIRC, 30(octal) , so if you added 1 to the address, you'd have to clear the sector to zero, and add one to the track address, also being aware that the track number could overflow. I learned a lot from that old machine. Rick Bensene The Old Calculator Museum http://oldcalculatormuseum.com

10 years

would like to find blue dg et head looking terminal to go with small eclipse

by COURYHOUSE＠aol.com

would like to find blue dg et head looking terminal to go with small eclipse this thing is a beauty and has a tiny side by side reel to reel deck just would be nice to have a terminal to display with it in the museum. drop us a line offlinst... ed sharpe archivist for smecc

10 years

Some amount of DG goodness

by marc.verdiell＠gmail.com

Oh, that blue 1970's psychedelic color! The fast line printer! The vacuum column drive (drool)! And it is alive! Congratulations! Marc

10 years

'New' PDP-11 prints

by jnc＠mercury.lcs.mit.edu

So, I've been going through all my PDP-11 prints, looking for ones that aren't already online (so I can scan/upload them). I have a couple (see later message), but this is about something else. In doing the above, I ran across an LSI-11 print set (MP-00706) which is about 340 pages long, and contains prints for all manner of boards, some of which do not show up (for reasons I don't understand) when looked for in a common search engine (Google, to be precise). I will eventually be adding them to my list of 'online by unfindable print sets': http://ana-3.lcs.mit.edu/~jnc/tech/FMPSOnline.html (which I have recently updated with more finds falling out of the search of my collection of prints), but: does anyone know of any other similar large compendiums of prints online? In particular, I'm hoping there's a later equivalent (this one's from October 1978) which would show a lot of the later QBUS boards which we don't have prints for. As I previously mentioned, I've gone through a number of PDP-11 print sets which are online (11/05, 11/05S, 11/23, 11/34, etc) in compiling the initial list, but it seems like there are more out there. Please let me know of any others you are aware of, so I can trawl them too! Noel

10 years

Self modifying code, lambda calculus - Re: ENIAC programming

by mark＠markesystems.com

> I wrote X.25 software in Fortran:-(. We had some machine specific routines One of my first professional jobs after college was with a company that created after-market hardware and software for Apollo workstations. Despite having a good Pascal, I was tasked with (and completed) a port of a scientific word processor package (WordMarc), all in Fortran (77, at least). Since I ended up being pretty familiar with both the language and environment, I used it again to throw together a simple 8080 assembler in about a day, too. ~~ Mark Moulding

10 years

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test-drb September 2015