test-drb January 2017

test-drb@ccmp.vtda.org

198 participants
283 discussions

Desparately seeking Cromemco chassis (UK)

by james＠attfield.co.uk

Wishing all here a very Happy New Year! Along with some other folks in 2017 I have decided I am going to ripple through all of my vintage systems and warm their beautiful and friendly caches. I won't have a problem with my BBC Micro, Atari 1040ST, Amiga 500's, 2000's, 3000 and 4000 and the PowerMac's but what I really would like is to bring my Cromemco back on line. I have the cards (DPU, 256KZ, 16FDC plus sundry others e.g. Quadart, IOP) and drives (Tandon TM100 5" and dual TM848 8") but although I have a naked Blitz Bus I lack a decent chassis. This is a plea for any kind soul with a spare or unwanted chassis who is prepared to let one go to help me out. Ideally a CS/3 chassis would be preferable however a Z2D, Z2 or even a System 1 chassis would be gratefully given a loving and permanent home. Naturally, given the weight of same, I expect I would have to pick up or arrange transport so regretfully any offers would have to be UK-based. The CS/3, and the Z2/Z2D had power supplies designed to handle a fully loaded bus of 21 S-100 cards (although I never handled one with more than 12 or so) and were one of those rare systems which could pass Navy certification i.e. survive being stood on by a rating in full gear and boots so were quite substantial. I would also be very interested in a 64FDC and any 5Mb or 20Mb IMI drives as I have a WDI-II controller, alternatively an STDC controller. James ---- James Attfield West Midlands, UK G8ZMP

7 years, 9 months

LGP-30 Memory Drum Update

by COURYHOUSE＠aol.com

In a message dated 1/3/2017 11:11:54 A.M. US Mountain Standard Time, elson at pico-systems.com writes: On 01/03/2017 10:58 AM, Cory Heisterkamp wrote: > While waiting for the machine, I decided to investigate the stuck drum. > This unit has 71 read/write heads plus what appears to be an inductive > pickup for the system clock. Upon closer examination I discovered multiple > heads in contact with the drum surface preventing rotation. And in the > process of removing the mounting bars that secure the heads only then did > damage become visible on a couple of tracks (scored oxide under the heads). Most likely the same issue as the G-15 we had. Dust was allowed to get into the drum area and pack under the heads. Probably if you pull the heads and clean them, it will restore clearance. Of course, the bearings may be bad, or will have to be replaced anyway as the grease may have hardened. > > > What I?m wondering is if anyone is familiar with the setup/adjustment > procedure for getting the heads set correctly. There *might* be a couple of > unused tracks I can relocate heads to, but my thought is that if half a > dozen heads were already in contact, then the rest may be perilously close > as well (swelled drum?). My odds of setting 71 heads perfectly on a 50 year > old worn drum is?well?not great. > If the drum can be set up to run true again (may need attention to bearings) then I think setting the heads up won't be that tough. I suspect it is done with a feeler gauge, this is low-resolution stuff with large gaps in the heads, so the heads probably run with a gap of at least .005" (~ 0.1mm) (I'd think, without actually knowing). > > For kicks, I tried to use a piece of cheap (=thin) (0.004?) notebook paper > as a feeler gage to see if I could identify the offending heads prior to > support removal. This was a no-go as clearance was too tight. So, is it > true these ride 0.001? off the surface? Well, it could be. That sounds really close for the vintage involved. So, maybe the drum or oxide has swelled. Anyway, if there is much damage to the oxide, it may not make sense to try to repair it. if the heads that jammed it left divots in the drum, or the surface is uneven (likely if swelling actually occurred) then it may require extreme efforts to repair. > > I suspect with temp and humidity changes, and given the age, I would be > better off building a solid state drum emulator for the 4KW mem, but > retaining the drum for the clock and possibly the 3 fast registers..if I > can get those (7) heads set correctly. > > > > Why not just replace the whole works? If you are going to replace the long lines with electronic memory, doing the short lines and the clock track should be trivial. I think a mid-sized FPGA could do it all quite easily. My guess is that if the surface is uneven, it may not read back data reliably. The high spots might be fine, the low spots will have dropouts. This is all assuming swelling was the culprit. It is also possible that machined parts suffered stress relief over the years. Wrought metal has stress imparted to it when rolled, and then machining will partially relieve the stresses, causing warpage. The warping continues over time. To eliminate this, critical parts are machined close to size, heat treated to relieve the stress, and then finish ground to exact dimensions. It is possible some of the stress wasn't relieved during manufacture. And, nobody expected a 195x machine to be running in 2017, especially as anybody in the computer business knew those transistors were right around the corner, and would almost certainly replace tubes. Jon Cory - then what holds the oxide to the drum? Horrible thoughts of what happens to binder layers on mag tape... flaking, sticky shed.... ecccshhh! I deal with this problem all the time on some of the historic video tape we have done conversion on out of our media lab.....

7 years, 9 months

PDP-10 Foonex

by bygg＠cafax.se

> Appeared here: > > http://github.com/PDP-10/FOONEX The web says: "Initial checkin whilst I figure out what format the files are" I took a quick look and guessed a little: #include <stdio.h> typedef unsigned long long w36; void pchar(char c) { c &= 0177; if ((c < ' ') || (c == 0177)) c = ' '; putchar(c); } int main(int argc, char* argv[]) { int wnum = 0; int c1, c2, c3, c4, c5; w36 w; int lh, rh; for (;;) { w = getchar(); w <<= 8; w |= getchar(); w <<= 8; w |= getchar(); w <<= 8; w |= getchar(); w <<= 4; c5 = getchar(); if (c5 == EOF) break; w |= (c5 & 0x0f); lh = w >> 18; rh = w & 0777777; c1 = (w >> 29) & 0177; c2 = (w >> 22) & 0177; c3 = (w >> 15) & 0177; c4 = (w >> 8) & 0177; c5 = (w >> 1) & 0177; printf(" %6o: %9llx %06o,,%06o", wnum, w, lh, rh); printf(" %3o %3o %3o %3o %3o \"", c1, c2, c3, c4, c5); pchar(c1); pchar(c2); pchar(c3); pchar(c4); pchar(c5); printf("\"\n"); wnum += 1; } return 0; } resulted in: 0: 7000037 000700,,000067 0 34 0 0 33 " " 1: 21f30 000000,,417460 0 0 4 37 30 " " 2: 894e5ba78 422471,,335170 104 123 113 72 74 "DSK:<" 3: 8d3e7ce8a 432371,,747212 106 117 117 116 105 "FOONE" 4: b0fa1c882 541750,,344202 130 76 103 110 101 "X>CHA" 5: 9f4d74d82 476465,,646602 117 123 56 115 101 "OS.MA" 6: 86ed9b972 415666,,334562 103 73 63 71 71 "C;399" 7: 0 000000,,000000 0 0 0 0 0 " " [snip] 777: 0 000000,,000000 0 0 0 0 0 " " 1000: 774e94374 356472,,241564 73 123 122 103 72 ";SRC:" 1001: 794ecd35c 362473,,151534 74 123 131 123 56 "<SYS." 1002: 9b3e749a8 466371,,644650 115 117 116 111 124 "MONIT" 1003: 9f49f4390 476447,,641620 117 122 76 103 110 "OR>CH" 1004: 833e9ae9a 406372,,327232 101 117 123 56 115 "AOS.M" 1005: 830d73372 406065,,631562 101 103 56 63 71 "AC.39" 1006: 6e810375a 335004,,033532 67 40 40 67 55 "7 7-" 1007: 9b87cad70 467037,,126560 115 141 171 55 70 "May-8" 1010: 62818b974 305006,,134564 61 40 61 71 72 "1 19:" 1011: 66d5d346c 315527,,232154 63 65 72 64 66 "35:46" 1012: 58822e4d2 261010,,562322 54 40 105 144 151 ", Edi" 1013: e88317940 721014,,274500 164 40 142 171 40 "t by " 1014: 9b361cd1a 466330,,346432 115 115 103 115 15 "MMCM " [and so on] Looks like a tape in core-dump format with a header page. Should be kindof trivial to process these into plain text automagically. --Johnny

7 years, 9 months

PDP-10 Foonex

by lars＠nocrew.org

Appeared here: http://github.com/PDP-10/FOONEX

7 years, 9 months

IA-1010 Z-80 board difficulties!

by Mark＠Misty.com

Hi, On Mon, Jan 02, 2017 at 10:32:28PM -0800, Richard Pope wrote: > Walter, > . . . . I appreciate all of this information. I have a revision 2.0 > board and my info shows U8 as a 96S02 multivibrator chip. I have tried > to find a replacement for this and I have not been successful. I believe this is a suitable replacement. I found it while getting the parts together necessary to build my bare IA-1010 Z-80 board. "AM26S02PC - Schottky Monostable Multivibrator ( 5 pcs ) - 16 Pin DIP Plastic" http://www.ebay.com/itm/261370092245 Mark -- Mark G. Thomas (Mark at Misty.com), KC3DRE

7 years, 9 months

ISO Compugraphic MCS-10 keyboard

by aek＠bitsavers.org

Pics of what I'm trying to find at http://www.retrocomputing.net/parts/compugraphic/mcs_keyb/ Bought one w/o kb or monitor and managed to locate a few floppies for it. CP/M 86 was available from CG, but I don't think there's much chance of ever finding that. Even just a dump of the microcontroller in the kb would be helpful. I'm not quite sure who the contact would be at retrocomputing.net to ask if they could dump the one in theirs. I have the PALs dumped and disassembled, will have those up on bitsavers later this morning.

7 years, 9 months

Hollerith cars available (ebay warning).

by jwsmail＠jwsss.com

Sorry for posting the National machine w/o an Ebay warning. Anyway anyone that has a home keypunch will possibly be interested in this guy. I have ordered up a pile, as I doubt they will show up this cheap unless someone takes it on themselves to manufacture them as the earlier discussions suggested. Not holding my breath for that. I don't personally care that there is a lot of crap printed on them, rather than the column indexes. The machines don't read that, and the top band is clear for my keypunches to write there with whatever is on the card. thanks Jim Has cases of 2000 and also cases of 5 x 2000 = 10000 cards (look for the 5 case auction separately) http://www.ebay.com/itm/272488557055

7 years, 9 months

Fix for 4.3BSD-Quasijarus bootstrap on CMD SCSI controllers

by derschjo＠gmail.com

Hi all -- Thought I'd share this fix with you all just in case someone in the future might make use of it. Long story short: Got myself a CMD 710/M UNIBUS SCSI controller with the intent to use it in my VAX-11/750, running 4.3BSD-Quasijarus. Unfortunately it won't boot (it hangs shortly after "loading boot" is printed to the console). VMS boots, NetBSD > 1.6 or so boots, Ultrix boots, but no luck with 4.3BSD. I spent some time adding some debug spew to the bootstrap (on SIMH) and testing (on the 750), and the hang is inside udcmd() in sys/vaxstand/uda.c. I then stumbled on this usenet post: https://groups.google.com/forum/#!msg/alt.sys.pdp11/61LZNTo9Dgg/Q6dI9om_LIEJ Which indicates a similar problem with a Viking controller on a different 4.3BSD variant. The code in Quasijarus is a bit different, but the cause is the same. The fix is: Change line 155 of sys/vaxstand/uda.c from: if(u->uda_ca.ca_rspint ==0) to: if(u->uda_ca.ca_rspdc & MSCP_OWN) Rebuild, and re-run disklabel to replace the bootstrap. Hope that helps someone else someday... - Josh

7 years, 9 months

Transporting an LGP-30

by blstuart＠bellsouth.net

On Thu, 12/29/16, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote: > Interesting factoid about the Bendix G-15: it was designed with the help of > one of the ACE people (Harry Huskey), and is basically a re-packaged ACE with > drum instead of delay lines. There's an interesting article by Huskey himself > in "Alan Turing's ACE" (by Jack Copeland) which discusses the G-15. Indeed. Huskey is probably one of the most influential, least known early pioneers. He was one of the engineers on the ENIAC, having designed the card reader and punch interface units. He spent some time at NPL and was one of the prime pushers behind the idea of building a pilot version of the ACE. When he returned to the US, he designed both the SWAC and the G-15. Later he was on the faculty at UC Berkeley where three of his advisees were Niklaus Wirth, Ken Thompson, and Butler Lampson. And he turned 100 early in 2016. BLS

7 years, 9 months

was: National Semi... is Apple ][ collectability (if any)

by COURYHOUSE＠aol.com

In a message dated 1/3/2017 1:09:50 A.M. US Mountain Standard Time, jwsmail at jwsss.com writes: On 1/2/2017 11:26 PM, Brad H wrote: > I brought the RFI thing up with him. No response. There is a legit Rev 1 there too asking $3500. I don't find Apple IIs below Rev 0 that interesting anymore, personally. I think even the legit guy would struggle to get much above $1500. The vintagecomputer museum guy on epay is selling mounted and framed motherboards now for $1500 (might not work noted). I guess someone would care about low ref Apple 2's but I'm not sure why there would be any interest. I've got one I bought with the original packing box, which I have picked and moved twice, which is rare for my collecting, but I don't know what makes any Apple 2 like that collectible. As in why are they collectible with low serials / part numbers. is there any documentation as to when they were made with those numbers that would make them significant? The numbers made as Raymond said would make most of us with Apple 2's millionaires I'd think unless they have some other significance. just curious. thanks Jim Jim the vintagecomputer museum guy wants a crazy price for a roll of teletype punch tape... I do not understand some of his prices. Ed#

7 years, 9 months

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test-drb January 2017