test-drb May 2020

test-drb@ccmp.vtda.org

163 participants
133 discussions

Re: Looking for a pair of DEC RL02 drives, working or otherwise

by stephenbuck＠mac.com

Hi Chris, I?m located in Boulder, Colorado. I?m fine with an RL02 that doesn?t work. If it can?t be fixed it can always occupy space in the rack. This is going into a museum and I might end up using an emulated drive behind the scenes for day-to-day use. Steve ?

4 years, 7 months

DIGI-COMP 1 enhanced (Joerg Hoppe)

by j_hoppe＠t-online.de

/Hi Michael, />>/I added a motor drive to my DIGI-COMP I, and wrote 4 web pages about />>/that device. />>//>>/See http://www.retrocmp.com/articles/digi-comp-1/ />>/or just the video https://youtu.be/D6GgxXRJXnw / > That is very cool! > The RICM has a DIGI-COMP, but we have not done much with it other than put > it on display. > > -- > Michael Thompson I attached the Arduino firmware and the "Bill Of Materials" with all 3D print files to http://www.retrocmp.com/articles/digi-comp-1/305-digi-comp-1-show-case-proj… So if you like ... kind regards, Joerg

4 years, 7 months

DIGI-COMP 1 enhanced

by j_hoppe＠t-online.de

Hi, > It it possible to get parts for a Digicomp? Mine needs some springs and > the thing that connects the clock to the whatever. I used rubber bands instead of springs. The article about 3D print DIY https://www.thingiverse.com/thing:1477209 contains instructions how to bend the wire crank. regards, Joerg ?> >/I added a motor drive to my DIGI-COMP I, and wrote 4 web pages about /> >/that device. /> >//> >/See http://www.retrocmp.com/articles/digi-comp-1/ /> >//> >/or just the video https://youtu.be/D6GgxXRJXnw /> >//

4 years, 7 months

Odd punched cards

by mhs.stein＠gmail.com

If I said 'EPT' anywhere I apologize; I'm talking about PPT (Punched Paper Tape) and EPCs (Edge Punched Cards). Here's a description of a series 'L' system, the successor to the 'E' series, containing "The reader could be used for loading programs faster. It could also be used for accessing user data from punched paper tape or from edge-punched cards." http://www.picklesnet.com/burroughs/descriptions/bltc.htm And pictures of the PPT/EPC perforator and reader (unfortunately the perf picture seems to link to the reader so you don't get a full-sized picture) : http://www.picklesnet.com/burroughs/gallery/bpgltc.htm- A great (downloadable) book full of pictures and specifications of computers of that era is "A Third Survey of Domestic Electronic Digital Computing Systems" (one of a series): https://books.google.ca/books?id=fZg8yAEACAAJ&dq=a+third+survey&hl=en&sa=X&… See P.179 for a well tricked out E101. Unfortunately people tend to dismiss this class of systems as 'only' accounting machines, largely because of their integrated keyboards and printer carriages based on the earlier electro-mechanical machines for operator familiarity, so there's little information and discussion about them. But they are definitely 'true' computers using the same technology as contemporary general-purpose systems, core memory, disk drives, etc., and as technology advanced IC memory, high-speed dot-matrix printers etc., and, in the latest models, multiple high-speed cassette drive systems used the same way as the big brother tape drives and almost as much fun to watch in action. Sorry for going a little OT; I'll do some digging for those cards... mike ----- Original Message ----- From: "Peter Van Peborgh" <peter at vanpeborgh.eu> To: "'Mike Stein'" <mhs.stein at gmail.com> Sent: Saturday, May 09, 2020 6:27 AM Subject: RE: Odd punched cards > M, > > An intriguing email. Also leaves me with more questions... And longings! > > My [PVP: ] comments are in your email below. > > Vintage computers forever! Many thanks, > > P > > -----Original Message----- > From: Mike Stein <mhs.stein at gmail.com> > Sent: 08 May 2020 16:45 > To: Peter Van Peborgh <peter at vanpeborgh.eu> > Subject: Re: Odd punched cards > > The systems that I'm familiar with that used EPCs were Burroughs 'E' series > accounting computers; the readers and perforators handled both PPT and EPCs > and the cards were a sort of random-access PPT. > > [PVP: ] I am having problems finding info on these two types of cards: EPT > and EPC. Can you point me in the right direction? > > If you were preparing an invoice, for example, you might have a set of cards > for the customer name and address and another (possibly different colour) > set for the line items; you'd enter the quantities and it would be printed > and punched out on PPT for the accounting functions. > > Still have some cards and the perfs and readers somewhere; must play with > them one day... > > [PVP: ] This is cruelty to animals! Is there ANY way you could dig up some > of these EPC and EPT cards for my collection/display? Talk to me about > postage, etc... > > > m > > ----- Original Message ----- > From: "Peter Van Peborgh" <peter at vanpeborgh.eu> > To: "'Mike Stein'" <mhs.stein at gmail.com> > Sent: Thursday, April 23, 2020 3:45 PM > Subject: RE: Odd punched cards > > >> Mike, >> >> 96-column cards I have, thank you. >> >> I used edge-punched cards to record scientific papers' details when I was >> doing research. Did any get used with computers, do you know? >> >> Many thanks, >> >> peter >> >> -----Original Message----- >> From: Mike Stein <mhs.stein at gmail.com> >> Sent: 23 April 2020 19:17 >> To: Peter Van Peborgh <peter at vanpeborgh.eu>; General Discussion: On-Topic >> Posts <cctech at classiccmp.org> >> Subject: Re: Odd punched cards >> >> How about 96 column and EPC (Edge Punched) Cards? >> >> ----- Original Message ----- >> From: "Peter Van Peborgh via cctech" <cctech at classiccmp.org> >> To: <cctech at classiccmp.org> >> Sent: Thursday, April 23, 2020 2:03 PM >> Subject: Odd punched cards >> >> >>> Guys, >>> >>> I got a positive response about the Port-A-Punch cards so no longer any >> need >>> to respond to this one. Very encouraging. >>> >>> Still looking for Jacquard cards and original Hollerith cards. Hope >> springs >>> eternal. >>> >>> peter >>> >>> || | | | | | | | | >>> Peter Van Peborgh >>> 62 St Mary's Rise >>> Writhlington Radstock >>> Somerset BA3 3PD >>> UK >>> 01761 439 234 >>> >>> "Our times are in God's wise and loving hands" >>> >>> || | | | | | | | | >>> >>> >> >

4 years, 7 months

Odd book

by jnc＠mercury.lcs.mit.edu

> From: Dwight Kelvey > There was a fellow that made a relay logic that could play tic tac toe What's with these new-fangled devices using _electricity_ anyway? :-) In high school, my math teacher (I think it was) used a couple of matchboxes and some beads to create a TTT device; he 'programmed' it by playing against it, and when the device lost a game, he pulled out the bead that indicated the device's previous move, so it could never make that losing move again. Pretty impressive, I thought... Noel

4 years, 7 months

MicroVAX 3100 Model 95 Ripple

by robert.jarratt＠ntlworld.com

Hello, I have recently been trying to improve the ripple on the output of my MicroVAX 3100 Model 95 PSU because occasionally it would fry a memory module. I replaced a bunch of capacitors, some of which had started to leak. However, the ripple does not seem much better. There is a scope trace here: https://rjarratt.files.wordpress.com/2020/05/microvax-3100-model-95-psu-ripp le-after-re-capping.png Ch1 is the 12V output and Ch2 is the 5V output. I had an old RD53 connected as a dummy load. It is possible that the memory was breaking because of occasional spikes that are worse, but I don't know. Does that seem OK? Thanks Rob

4 years, 7 months

DIGI-COMP 1 enhanced

by j_hoppe＠t-online.de

Guys, I added a motor drive to my DIGI-COMP I, and wrote 4 web pages about that device. See http://www.retrocmp.com/articles/digi-comp-1/ or just the video https://youtu.be/D6GgxXRJXnw best regards, Joerg

4 years, 7 months

Facit N4000 Schematic

by ard.p850ug1＠gmail.com

>From time to time there are posts here about the Facit N4000 paper tape punch/reader unit. The one that looks like a Facit 4070 with a tape reader on the front (in fact the punch mechanism is much the same as that in the 4070). I have reverse-engineered mine and traced out the schematics. Of course it's one of my hand-drawn ones but I think it's mostly legible. If anyone wants it I am happy to send out a copy (but as ever I'd rather send it out once and have somebody else pass it on) -tony

4 years, 7 months

Odd book

by jnc＠mercury.lcs.mit.edu

So, I've come across an odd book that might interest some here: "Achieving Accuray: A Legacy of Computers and Missiles", by Marshall William McMurray. The first couple of chapters merely re-tell the story of earliest computers (pre-elecronic and electronic), up through the IBM 701, Elliott 401, NCR 304, SAGE, CDC 6600, IBM 7090, etc. Competent, but nothing special. Then it gets interesting, though. Chapter 4 is "Small Magnetic Drum Computers of the 1950s", and it covers a bunch of machines I'd never heard of: JAINCOMP B-1 (!), MONROBOT III (!!), CADAC 101, 102 (!!!) and on and on. Chapter 5 is "Real-Time Control Computers", and it covers a long group of machines: ALWAC I, II, III; Univac Athena; Autonetics Verdan D9A-L; Librascope C-141 to name but a few. Pure gold, this chapter and the one before - retrieved a lot of machines from the memory hole. Chapter 6 is "NASA Control Computers", and it covers the usual suspects: IBM ASC 15, IBM LVDC, IBM GDC, Librascope Centaur, AGC, IBM 4Pi. Some of these are covered elseshere, but it's nice to have them all in one place. Chapter 7 is "Late-Model High Speed Supercomputers", with quite a range: starting with Cray 1, Sun, SGI, then the various ASCI array multi-processor systems at LLNL, etc. It then moved over to missiles, and goes through a similar progression, starting early, with some details of WWII era stuff (e.g.Hs 293's), then a chapter on V-1's amd V-2's and their derivatives. More chapters on "Early US Missile Programs", NAA's inertialguidance work and its applications up through Polaris, Titans, etc. Then more on later US missiles and their guidance systems, such as Minuteman, Trident and MX. A lengthy Chapter 13 is "Soviet and Russian Land-Based Missile Systems", which doesn't have quite the detail of the US chapters (in which the authot was personally involved), but is still novel. Another chapter then finishes with Soiet/Russian naval missiles. A very unusual and off-beat work. Noel

4 years, 7 months

DIGI-COMP 1 enhanced (Joerg Hoppe)

by michael.99.thompson＠gmail.com

> > From: Joerg Hoppe <j_hoppe at t-online.de> > Subject: DIGI-COMP 1 enhanced > > Guys, > > I added a motor drive to my DIGI-COMP I, and wrote 4 web pages about > that device. > > See http://www.retrocmp.com/articles/digi-comp-1/ > or just the video https://youtu.be/D6GgxXRJXnw > > best regards, > Joerg > That is very cool! The RICM has a DIGI-COMP, but we have not done much with it other than put it on display. -- Michael Thompson

4 years, 7 months

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test-drb May 2020