test-drb

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101090 discussions

by silent700＠gmail.com

I've just picked up an old Burroughs terminal, model# appears to be MT-985, and I'm having trouble finding documentation for it. It came with a manual for the ET-1100 model which provides some clues, but the key sequences to get into the setup for baud rate, etc appear to be different. Anyone have any experience with these? It's a cute little terminal and the keyboard has a key lock on it - never seen that before.

18 years, 11 months

Help identifying a capacitor

by mbbrutman-cctalk＠brutman.com

I'm trying to reverse engineer a board that I have and I've bumped into a component that I don't understand the markings on. If you would like to help, a picture can be found here: http://brutman.com/2007_0717_124331.JPG I suspect it is a capacitor, but the markings are strange to me. The capacitor behind it has '104' written on it, so I understand that to be a 0.1uF capacitor. But the one in the foreground marked '35+' is strange to me .. (My apologies in advance - I'm a software person, but I'm trainable.) The identified capacitor and the suspect capacitor tie together two ground plane, so I suspect it is for power smoothing. Thanks in advance, Mike

18 years, 11 months

Teletype Model 40 tape unit

by legalize＠xmission.com

Ebay # 190133198900 -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 11 months

2901 OT

by wbblair3＠yahoo.com

Just as an off-topic diversion from a subject that I don't think is actually off-topic, here are a number of die photos including some from the AMD 29xx and 29xxx series and others: http://diephotos.blogspot.com/ ------------------------ "The war is not meant to be won, it is meant to be continuous. -- Eric Blair (aka George Orwell), "1984" ____________________________________________________________________________________ Sick sense of humor? Visit Yahoo! TV's Comedy with an Edge to see what's on, when. http://tv.yahoo.com/collections/222

18 years, 11 months

2901 OT

by wbblair3＠yahoo.com

> Does anyone have the datasheets on the AMD 2901 bit slice? > I have the data sheet on the 2901A/2901B/, but it would be nice to have > some timings from the 2901. Although I haven't looked, I suspect that its would be in the 33MB PDF 1979-AMD2900.pdf found here: http://www.electronballet.com/Databooks/ It's the AM2900 Family Databook. Best, Bill ------------------------ ?Shoot THE DUCK! Shoot THE DUCK!? - Bugs Bunny ____________________________________________________________________________________ Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel and lay it on us. http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7

18 years, 11 months

Classic Operating Systems Book

by technobug＠comcast.net

If you have $20 to spare, Edward Hamilton Booksellers <http:// www.hamiltonbook.com> has an interesting volume: item 612139X, Classic Operating Sytems: From Batch Processing to Distribute Systems. You can read a more complete description at <http:// www.springer.com/west/home/generic/search/results? SGWID=4-40109-22-2182421-0> (listed at $74.95). CRC

18 years, 11 months

cctalk Digest, Vol 47, Issue 32, Message 1, LEO (1950) NGTE

by mike＠brickfieldspark.org

> From: Jules Richardson <julesrichardsonuk at yahoo.co.uk> > Subject: Re: [personal] cctalk Digest, Vol 47, Issue 29, Message 9 > Subject: LEO (1950) > To: General Discussion: On-Topic and Off-Topic Posts > Long-gone presumably? Sites seem to often get cleared of fixtures and > fittings > really quickly in the UK compared to other countries for some reason. > Plus, > even if there was anything left, the kids seem to trash everything they > can > and of course the petty thieves move in for metals like copper. > NGTE as a site is sitll there in its entirity, Google for it and you will find lots of Urban Exploration groups listing NGTE. The site is still partially used, the computer suite is one of the buildings you cannot get into so some of the mainframes - might - just still be there, but who to contact ? to find out. >> Tesco wants to build a 1,000,000 sq ft distribution depot, >> apparently it will be one of the biggest buildings in the Uk,.with 1600 >> 38 ton lorry (non motorway) movements a day, nothing good will come of >> it. > > The government won't need a national ID database and ID cards, they'll > just > borrow Tesco's ;) >

18 years, 11 months

Unknown Acorn Scematic

by mike.hatch＠mclennan.co.uk

Whilst going through some old schematics I found one for an Acorn, although it does not say which type, beleive it my be a BBC Model B, could be wrong. Its here if needed - http://www.brickfieldspark.org/temp/acorninfo.htm Mike (Aka TerrapinDundee)

18 years, 11 months

Looking for old Computer Shoppers . . .

by dgreelish＠mac.com

Hello, I'm looking for copies of Computer Shopper from the year 1992 (late '91 - early '93). Anybody have some copies laying around the house? You know, when they were really thick and big? Since I'm requesting, I'm also looking for some missing issues of INFO=64 magazine . . . anyone? Thanks for your help. Best, David David Greelish classiccomputing.com The Classic Computing Podcast Home of Computer History Nostalgia Stan Veit's History of the Personal Computer Audio Book Podcast

18 years, 11 months

1966 Mag: Build NE-2 Neon Bulb Computer - scan available

by ajp166＠bellatlantic.net

> >Subject: Re: 1966 Mag: Build NE-2 Neon Bulb Computer - scan available > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Wed, 18 Jul 2007 00:04:29 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Allison wrote: > >> A dial comes from an old phone, check a thrift. > >> The NE-2s are still very available from most decent electronic >> parts suppliers. > >Both are figments of your imgination - none around - thrift stores >or decent electronic parts suppliers . >But I did download the PDF so some day in the far future... I keep forgetting you live in the heart of unobtainium. Out on the fringes things can be found. Allison

18 years, 11 months

Ebuyer.com runs on a Commodore 64!

by dgreelish＠mac.com

Has anyone else read this short tech news piece? Wow, how do they do that? http://www.theregister.co.uk/2007/07/07/ebuyer_runs_site_on_commodore64/ Best, David David Greelish classiccomputing.com The Classic Computing Podcast Home of Computer History Nostalgia Stan Veit's History of the Personal Computer Audio Book Podcast

18 years, 11 months

LEO (1950)

by RodSmallwood＠mail.ediconsulting.co.uk

Amongst other references I found this In 1951 the LEO I computer was operational and ran the world's first regular routine office computer job. About the "Lyons Electronic Office" (LEO I) The LEO I used 5,936 valves, plus another 300-400 in auxiliary equipment. The LEO used 64 mercury tubes for storage (twice the memory capacity of the EDSAC machine built in Cambridge). Each memory tube was 5 feet, four inches in length and weighed half a ton. The computer was controlled from a control panel, with several oscilloscopes set up to monitor contents of the storage area. The machine also had a speaker installed and programmers could hear the sounds generated as LEO performed certain calculations. The programmers became so accustomed to certain frequency variations, that they could detect something was wrong with a program by the sounds produced through the speaker. The programmers also used this speaker arrangement to generate some of the first "computer music." Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Roger Holmes Sent: 18 July 2007 14:24 To: cctalk at classiccmp.org Subject: Re: LEO (1950) > Date: Tue, 17 Jul 2007 20:43:50 +0100 > From: "Rod Smallwood" <RodSmallwood at mail.ediconsulting.co.uk> > > I happened on the program by chance. It might have been called > Disappearing Britain. A lot of it was contemporaneous and could have > been a Lyons publicity film. (or at least bits of one). I suspect our > friends at the National Film Archive might know. I suspect it is a contemporary promotional film on the Leo II dated 1957 and mentions that it has been working since 1953 - referring to Leo 1 I think, it is black and white and if that's it, I have it on a DVD published by Buzz KnowledgeWorks which I bought on eBay. > > I inadvertently made an ambiguous statement. By commercial I meant its > use, not its availability for sale. I knew what you meant. Most early designs were one or two off scientific machines, price no object. > Where would you start to design such a thing? Valves yes.. 12AT7 > Bistables as binary counters. Neon devices such as dekatrons as > decimal counters. RVL (Resistor Valve Logic). Storage = Ferrite Cores, > Tape, Drum possibly. I'm not sure many commercial machines were made with valves logic and a main memory of core. Transistors and core main memory often came in together. The ICT1200 series (AKA Hollerrith Electronic Computer) was drum main memory and valves but its replacement the ICT1300 series used "high speed switching transistors" and core memory with backing store of drum and optionally tape. > I once saw a Univac FAST RAN Drum memory. What a lump!!!

18 years, 11 months

CRTs, LCDs and image capture [was 1966 Mag: Build NE-2 Neon Bulb Computer - scan available]

by jfoust＠threedee.com

At 10:59 AM 7/18/2007, Ethan Dicks wrote: >I have had that specific problem with RCA 1861 "Pixie" graphics - I >can get viewable images on 1970s-era CRTs and TVs with no problem, but >I could not, for example, get a stable picture with an Apple 5" CRT >(used with the Apple IIc line), or a DEC VR201 (+12VDC/RS170 mono >monitor for Rainbow, DECmate, Professional, etc.) nor any sort of >recently-manufactured TV or LCD. Depending on the exact output device >in question, either I see pixels but can't get a frame to properly >lock, or I don't see anything at all. Mono video isn't too hard to decipher on a 'scope. I would guess there's a half dozen ways to mis-conform, as well as a half-dozen ways that older TVs did not reject out-of-spec signals. - John

18 years, 11 months

1966 Mag: Build NE-2 Neon Bulb Computer - scan available

by wbblair3＠yahoo.com

I can't find the beginning of this thread and I see no links to a scanned magazine article in any reply to the original post. Can someone please give me the link to this scan if one was offered? Best, Bill ------------------------ ?Shoot THE DUCK! Shoot THE DUCK!? - Bugs Bunny ____________________________________________________________________________________ Got a little couch potato? Check out fun summer activities for kids. http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&…

18 years, 11 months

LEO (1950)

by roger.holmes＠microspot.co.uk

> Date: Tue, 17 Jul 2007 20:43:50 +0100 > From: "Rod Smallwood" <RodSmallwood at mail.ediconsulting.co.uk> > > I happened on the program by chance. It might have been called > Disappearing Britain. A lot of it was contemporaneous and could have > been a Lyons publicity film. (or at least bits of one). I suspect our > friends at the National Film Archive might know. I suspect it is a contemporary promotional film on the Leo II dated 1957 and mentions that it has been working since 1953 - referring to Leo 1 I think, it is black and white and if that's it, I have it on a DVD published by Buzz KnowledgeWorks which I bought on eBay. > > I inadvertently made an ambiguous statement. By commercial I meant its > use, not its availability for sale. I knew what you meant. Most early designs were one or two off scientific machines, price no object. > Where would you start to design such a thing? Valves yes.. 12AT7 > Bistables as binary counters. Neon devices such as dekatrons as > decimal > counters. RVL (Resistor Valve Logic). Storage = Ferrite Cores, Tape, > Drum possibly. I'm not sure many commercial machines were made with valves logic and a main memory of core. Transistors and core main memory often came in together. The ICT1200 series (AKA Hollerrith Electronic Computer) was drum main memory and valves but its replacement the ICT1300 series used "high speed switching transistors" and core memory with backing store of drum and optionally tape. > I once saw a Univac FAST RAN Drum memory. What a lump!!!

18 years, 11 months

Looking for RX211 and/or RXV21

by pat＠computer-refuge.org

I'm looking for an RX211 (M8256) and/or RXV21 (M8029) to go with the RX02 I just picked up (don't know if it works yet)... less than "eBay Store" prices would be nice. :) Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

18 years, 11 months

Magazines available

by rcini＠optonline.net

All: A chap in the Beantown region emailed me with a list of magazines he has that he needs to find a home for. If anyone is interested, let me know and I?ll pass on his information. Here?s what?s available: > Apple II Computers > 1" APDAlog (Apple Developers) 1987-89 > 5" Apple Orchard 1980-84 > 1" applesauce 1981 > 11" Call-A.P.P.L.E. 1981-89 > 5" (Hardcore) Computist 1987 > 2" Peelings II 1982-84 > > Computers, esp. Microcomputers > 3" one each: MACazine, etc 1980-87 > > Technical Specialized Computers/Electronics > 2" C Users Journal 1989 > 4" Dr. Dobb's Journal of Software Tools 1983-89 > 5" Embedded Systems Programming 1989-92 > 5" MicroSystems Journal 1984-88 > 1" Computer Smyth 1985-86 - Vol.1 No.1+ Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://highgate.comm.sfu.ca/~rcini/classiccmp

18 years, 11 months

[personal] cctalk Digest, Vol 47, Issue 29, Message 9 Subject: LEO (1950)

by Billy.Pettit＠wdc.com

Mike Hatch wrote: > Tescos are killing our computer history - ? to qualify - The National Gas Turbine Establishment (NGTE, Farnborough) has been partially derilict for the last 10 years or so, on that site were an Elliott 803B, SDS9300, DEC PDP-7 and 11-05, and more, I helped maintain them. Tesco wants to build a 1,000,000 sq ft distribution depot, apparently it will be one of the biggest buildings in the Uk,.with 1600 38 ton lorry (non motorway) movements a day, nothing good will come of it. I'd love to get hold of the PDP7. ------------------------- Billy wrote: Not certain if anyone on the list is aware, but the UK is now exporting this fine establishment. One of the very first Tesco stores in the US is being built less than a mile from my house in Laguna Woods. (The huge distribution centers are already completed.) Turnabout seems fair play after what we gave the UK - MacDonald's, KFC, Pizza Hut, etc. Billy

18 years, 11 months

cctalk Digest, Vol 47, Issue 29

by wbblair3＠yahoo.com

> cclist at sydex.com wrote: > Here's a Wikipedia article about one of the early pioneers in ferrite > logic, Hewitt Crane: > > http://en.wikipedia.org/wiki/Hewitt_Crane And here's a ground-breaking computer that contributed tremendously to the development of core memory: http://en.wikipedia.org/wiki/Whirlwind_Computer and the excellent book about it: >From Whirlwind to MITRE: The R&D Story of The SAGE Air Defense Computer http://tinyurl.com/2987kc Best, Bill ------------------------ ?Shoot THE DUCK! Shoot THE DUCK!? - Bugs Bunny ____________________________________________________________________________________Ready for the edge of your seat? Check out tonight's top picks on Yahoo! TV. http://tv.yahoo.com/

18 years, 11 months

Replacement NorthStar Horizon Wooden Case Covers

by lynchaj＠yahoo.com

Hi, If you are interested in purchasing a replacement wooden case cover for a NorthStar Horizon computer, please contact me. Thank you. Andrew Lynch

18 years, 11 months

cctalk Digest, Vol 47, Issue 30, message 30, identify a capacitor

by mike＠brickfieldspark.org

> Message: 30 > Date: Tue, 17 Jul 2007 17:16:16 -0600 > From: "Michael B. Brutman" <mbbrutman-cctalk at brutman.com> > Subject: Re: Help identifying a capacitor > Some of what I'm reading says put the capacitor near the power supply, > and other things are saying get it as close to the chip as possible. > > The board I posted about is not optimal in this regard. It's an ISA bus > to PCjr bus adapter, so there is no TTL logic anywhere on the board - > the individual ISA cards have the TTL (and hopefully bypass capacitors). > In this application was the designer just trying to 'clean up' the > voltage sources for the TTL on the cards a little bit? > >From some years in pcb design shop. Bulk decoupling where the power enters the board 10-100uF + 0.1uF. Then a 0.01-0.1uF per Ic (for TTL that is). Keep the traces from the power pins to caps as short and fat as possible. Powers should ideally be planes or gridded traces. Newer logic families / packaging (TQFP, PLCC Etc), usually have very specific decoupling requirements set my the manufacturer

18 years, 11 months

[personal] cctalk Digest, Vol 47, Issue 29, Message 9 Subject: LEO (1950)

by mike＠brickfieldspark.org

> Message: 9 > Date: Tue, 17 Jul 2007 10:29:07 +0100 > From: Rob <robert at irrelevant.com> > Subject: Re: Vol 47, Issue 28, message 10, Subject: LEO (1950) > To: "General Discussion: On-Topic and Off-Topic Posts" > > .. except i had a sudden thought, and checked, and in the couple of > years since I last drove past the site, a Tesco supermarket has > apparently sprung up... Neither multimap.com or google earth > satellite photos have yet caught up... > > Sigh.. > Tescos are killing our computer history - ? to qualify - The National Gas Turbine Establishment (NGTE, Farnborough) has been partially derilict for the last 10 years or so, on that site were an Elliott 803B, SDS9300, DEC PDP-7 and 11-05, and more, I helped maintain them. Tesco wants to build a 1,000,000 sq ft distribution depot, apparently it will be one of the biggest buildings in the Uk,.with 1600 38 ton lorry (non motorway) movements a day, nothing good will come of it. I'd love to get hold of the PDP7.

18 years, 11 months

[personal] cctalk Digest, Vol 47, Issue 30 Capacitor ident

by mike＠brickfieldspark.org

> I'm trying to reverse engineer a board that I have and I've bumped into > a component that I don't understand the markings on. If you would like > to help, a picture can be found here: > > http://brutman.com/2007_0717_124331.JPG > That is a Tanatalum bead capacitor, 1uF 35V Dc rating, the + is for the +ve lead, which is a different length to the -ve lead when the component is new before soldering. 104 is 10 +0000 pf, 100,000 pf, 0.1uF, voltage rating unknown but probably in the 50Vdc-63Vac range. A common pairing for bulk decoupling on power lines or planes.

18 years, 11 months

TTL homebrew CPUs

by julesrichardsonuk＠yahoo.co.uk

I've been thinking more and more this last week about designing a CPU to be built from TTL logic ICs, purely as an interesting exercise. I'm thinking of a microprogrammed design with a pretty minimal register count - but as speed is never going to be a defining aspect anyway using commodity TTL, I'm thinking of going for a bit-serial ALU to keep the parts count down. Keeping the raw components pretty basic is another desired goal - no custom off-the-shelf ALU chips, gate arrays etc. Questions: have any others on here done stuff like this, or have any pointers to good resources? I'm learning as I go along here, flicking through technical manuals for 8-bit CPUs etc. and gleaning what I can from the web. MAGIC-1 is about the most comprehensive online resource I've found so far, but I believe it's a pure parallel core, and plus it's *way* more feature-rich that what I'm aiming for. I'm not interested in running UNIX-a-like software, or giving it hard drive interfaces or network stacks - I just think it'd perhaps be fun to design and later build something from scratch to do basic computation. cheers Jules

18 years, 11 months

1966 Mag: Build NE-2 Neon Bulb Computer - scan available

by ajp166＠bellatlantic.net

> >Subject: Re: 1966 Mag: Build NE-2 Neon Bulb Computer - scan available > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Tue, 17 Jul 2007 12:22:41 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Bob Bradlee wrote: > >> And never dialing Zero! >> otherwise an operator error will occure :) >Drat... I can't get all the parts. :) >Where do you get a telephone dial now days ... If I got the >phone with a dial it would work better than the $10 one I have. >The neon bulbs may be hard to find , the ones now days have >a built in resistor. A dial comes from an old phone, check a thrift. The NE-2s are still very available from most decent electronic parts suppliers. The trick to age NE-2s is run them at 50% over rated for a week (at lest 40 hours) and they will stabilize nicely. If you need to grade/match the aged NE-2s a 500hz relaxation osc and a scope will allow viewing the upper (fire voltage) and lower (extinguish) voltage as well as sensitivity to light very quickly. Hint, light should be incandecsent or the osc will try to sync on the flourescent flicker. Allison

18 years, 11 months

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