- test-drb@ccmp.vtda.org - classiccmp.org

Using vintage computers in the classroom

by mark.kahrs＠gmail.com

The last time I taught assembly language programming, I decided to include the PDP-11 as an example of addressing modes. This is because Patterson and Hennesey just use MIPS --- it's a good pedagogical method but then when the students hit the real world they wouldn't know an address mode from ??? I also had them think about the VT-40 as an example --- I thought they would like that kind of graphical machine (I was wrong of course). If I was more prepared and had a full graphical simulator, that would have helped.

16 years, 3 months

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SS50 to Exorbus adapter found

by chrise＠pobox.com

I was going through some boxes of parts for my SWTPC 6800 collection and I found an unpopulated PCB with SWTPC logo on it and date 1978 which appears to be an SS50 to Motorola Exorbus adapter. It has SS50 connectors on the bottom edge and the 43/86-pin Exorbus connector footprint on the top edge. Looks like locations for two DIPs, one 20-pin and one 8-pin, a voltage regulator and a few passives. The board is 8" wide by 2" high. I have no idea where this came from or why I have it. Does anyone know what it might be for? ie, does it adapt an Exorbus memory or peripheral to SS50 bus or does it adapt an Exorbus CPU to SS50?? I can send photos of the board to anyone that is interested. It appears to be an authentic SWTPC design/product rather than someone's homebrew project or a third party product. So, I am interested in learning more about it. Chris -- Chris Elmquist

16 years, 3 months

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Leaving computers on... (was Re: Disc analyser news update)

by dm561＠torfree.net

Date: Sun, 28 Mar 2010 18:00:33 +0100 From: Liam Proven <lproven at gmail.com> Subject: Re: Leaving computers on... (was Re: Disc analyser news update) On Sun, Mar 28, 2010 at 5:26 AM, Joost van de Griek <gyorpb at gmail.com> wrote: > On 26 March 2010 02:58, Liam Proven <lproven at gmail.com> wrote: > >> On Thu, Mar 25, 2010 at 7:42 PM, Josh Dersch <derschjo at mail.msu.edu> wrote: >> >>> I was thinking more of the battery in the original Mac Portable (which I >>> know is not what you're referring to). ?The portable weighed 16lbs, due in >>> no small part to the lead-acid battery it used. >> >> Yes, that was my guess, too. Only laptop-/style/ portable I ever even >> heard of with a lead-acid battery. > > PowerBook 100. Basically a repackaged Portable. --------------------------------------------------- The Sharp PC-5000 also had a lead-acid battery; according to them, L-A has a longer shelf life, charges faster, and is actually smaller and lighter for the same power than the NiCds of the day. mike

16 years, 3 months

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Using vintage computers in the classroom

by lynchaj＠yahoo.com

> -----Original Message----- > From: cctalk-bounces at classiccmp.org > [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Michael Black > Sent: Sunday, March 28, 2010 4:28 PM > To: cctech at classiccmp.org > Subject: Using vintage computers in the classroom > > Hello cctech community, > > I am a computer science professor and an avid collector and restorer > of old computers, which I routinely use in my classes. (I am also a > long-time lurker on cctech, but haven't posted much yet, I'm afraid.) > I am interested in chatting with other professors and teachers who use > working demonstrations of vintage technology in their classes. I am > aware of many cases where professors have taught courses on computer > history, used pictures and simulations of vintage computers, or took > students on field trips to computer museums. However, I am > particularly interested in examples where professors bring actual > working vintage equipment into the classroom (like a pdp-11 or a > teletype machine) and tried to teach their students to operate it. > Has anybody on this list tried it or know of people who do it? > > Thanks, > Michael Black [AJL>] Hi! You are welcome to use the N8VEM project for educational purposes. I designed it with use in education as its primary purpose. It could be readily used to teach fundamental computer hardware and software principles in an easily illustrated manner. Starting with a blank sheet of paper and building up the basic conceptual elements in a process which results in a simple working microcomputer would be educational and highly entertaining. Add some devices like the ECB backplane and the ECB bus monitor and you can show the CPU operating in single step mode, the effects of reset, and all kinds of computer operation. The N8VEM SBC is simple and inexpensive enough that it can be built by beginners, as many are already, and normally works the first time. It works by itself interfacing to a serial port although it can be expanded to video boards, floppy and IDE disks, and even custom peripherals. http://n8vem-sbc.pbworks.com/ http://groups.google.com/group/n8vem I hope this helps. Thanks and have a nice day! Andrew Lynch

16 years, 3 months

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Disc analyser news update

by classiccmp＠philpem.me.uk

Hi guys, Quick update regarding the disc analyser... Latest news is: * The USB interface is now running properly at full speed. Write-to-buffer has gone from 84Kbytes/sec to over 180 with two small firmware tweaks. Read speed is a little under 250Kbytes/sec, which means the entire 512K buffer can be read out in a shade over two seconds. It's not going to win me any awards, but I think it's plenty fast enough. * It Has A Name! One of my friends suggested "DiscFerret" partly as a slight dig at the Catweasel. The name has stuck to the point where I've... um... registered a .com domain name for it... (hey, it only cost ?12). I'll be setting up the site as soon as I find a nice Wiki package that isn't bloated to the size of a small main-sequence star (*koff* Mediawiki). * Schematics are basically done. I need to test the power supply section, which is on the to-do list for a bit later on. Soldering down the QFN-packaged power regulator IC will be interesting. * There's an external power output for disc drives. It provides +12V at 1.5A and +5V at 1.5A. Perfect for running small 3.5in drives, and saves a mains socket. Haven't decided on a connector, but the +12 is fed directly from the input power supply, so if you connect a 15V PSU you'll see 15V on the EPS output. * Power supply can accept between 9 and 15V, though it is specified to operate with peak efficiency at approx. 12V. Input is reverse-polarity protected with a grounded-gate low-Rds(on) MOSFET. I'll probably be building up a prototype power supply board tonight or tomorrow, and giving that a good beating with a homebrew DC load. I think I've got some MJE3055s and trimpots somewhere, though whether they'll work with Vce=1.2V remains to be seen (I suspect a MOSFET might work better). But first I need to get my paws on some 0.5mm carbide drill bits. There are a couple of vias on that board that are in a really tight spot... I make no secret of the fact that it was designed to be commercially manufactured, not haphazardly assembled by some semi-skilled engineering student in a garden shed (i.e. me!) The plan for those is to drill out the holes, push in a resistor leg flush with one side, solder on one side, cut and file flush on the other side, then solder that side too. I figure that should be a tight enough fit that the wire won't be going anywhere... and if that doesn't work there's always 26SWG tinned copper wire. Cheers, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

16 years, 3 months

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cctalk Digest, Vol 79, Issue 56

by marvin＠west.net

From: Josh Dersch <derschjo at mail.msu.edu> > (As a related aside, is there *anywhere* one can get hard-sectored 5.25" > floppies these days?) People have been known to make their own 5 1/4" hard-sectored disks. I don't remember the details, but the basic idea was to take a 5 1/4" disk drive to hold the disk, make an index wheel for the holes, add a hole punch, and then just add time.

16 years, 3 months

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Does a Northstar S-100 Bus Horizon Classify as a Classic

by acheel＠internode.on.net

Hi Dave, Interested to read about your Northstar S100 bus computer I have two of these withdual 51/4 disk drives sitting in my shed here in Adelaide South Australia I think I also have some manuals and software somewhere in the shed as well Are these of any value ? I also have some DEC desktop comuters and screens, disk units and tape units along with some operating software Kind regards Andy Cheel

16 years, 3 months

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Probably offering TC11 controller

by hachti＠hachti.de

Hi folks, I'll most probably offer a TC11 controller for sale in the next days. The controller connects to a pdp11's Unibus and can handle up to eight TU55/TU56 tape transports (i.e. four TU56). It is configured for TU56 control levels ("integrated circuit"). Ebay would probably be the easiest way to handle a transaction with overseas buyers. Are there interested persons willing to pay nearly USD 150 for shipping? Regards, Philipp

16 years, 3 months

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IBM Monochrome "Black and White" Parallel card double iimage

by billdeg＠degnanco.com

> This is certainly not a capacitor problem... > > I think this board uses 2144s as the video memory > So my first guess is to replace the RAMs. > > -tony > > ---- > > I'd be looking for a stuck address bit, or possibly a failed RAM chip > My money's on a 74xx chip (possibly a counter, buffer or multiplexer) > that's had an output fail open. > > Phil > > ----- > Along with Phil's suggestion of memory addressing issues resulting in a > double-scan of the memory, the staggering of the images suggests interlacing > might be occurring when it shouldn't be. Sometimes it is possible to tweak the > V/H-hold controls enough on monitors to end up with interlacing occurring when > it shouldn't. Can you discern whether each of the scan images contains a full > set of lines vs half the number of lines? > > I hate to ask, but what sort of monitor is this being displayed on? > IIRC the scan rate for MDA was higher than NTSC and I'm not not sure whether an > NTSC monitor would sync up or sync down to half the scan rate. > > Brent ----------------- Thanks for the feedback. I am using a standard IBM monochrome monitor. I tested the monitor with another known-working card, and I also tried another monitor. The problem is with the display card. This is one of the original black connector versions of the IBM 1904057 XM 407 display cards. It has 9114 RAMs in it, not socketed of course, so I think if I can probe each RAM chip first to ID the bad chip it'd be more efficient. I would similarly have to check the 74L chips. oy! Bill Degnan

16 years, 3 months

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Data I/O29A

by mdelepeleire＠hotmail.com

Hello, I cannot find doc informing how to send ie an .HEX file from Hyper terminal to my programmer, when the programmer sends a file to the cpu the format is a sort of a start character, the address of the first byte and then a series of : HH HH HH HH HH etc where H stands for a hex symbol. Do I need to translate the Intel Hex file or how can I send an OMF-51 file? Do I have to use another communication program?? Thanks if you can help me. Marc De Lepeleire _________________________________________________________________ Hotmail: Trusted email with Microsoft?s powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969

16 years, 3 months

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slashdotted - home built turing machine

by rdawson16＠hotmail.com

Did you guys catch this: http://aturingmachine.com/ Cool! Randy _________________________________________________________________ The New Busy is not the old busy. Search, chat and e-mail from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID27925::T:WLMTAGL:ON:…

16 years, 3 months

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IBM Monochrome "Black and White" Parallel card double

by billdeg＠degnanco.com

> > If it's the original IBM5151 monitor, remember there's no horizontal > oscillator in the monitor. The Hsync (or more correctly HDrv, which is > what IBM called it) output from the MDA card goes to the base of the > horiztoal driver transistor, the collector is then transformer-coupled to > the base of the horizotnal output transistor. > > This means a 5151 will try to run at whatever freqeucny you give it, the > horizotnal output stage is likley to protest if it's way off, though. I > don;t think that if you give it an HDrv of the wrong frequency it will > ever give you a double image. > > -tony > It is a 5151. I was able to reproduce the problem on a newer monochrome monitor. bd

16 years, 3 months

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HP 64000 relocatable file format / assembler

by classiccmp＠philpem.me.uk

All this talk about the HP 64000 has got me thinking... The HP 165xB Inverse Assembler Toolkit includes a DOS-based table assembler that appears to be derived from something used on the HP 64000, and it spits out what the manual calls a "HP 64000 format relocatable object file". This is what the analyser loads to run an IA. Did HP ever publish a spec for the .R (relocatable object) file, or has it ever been successfully reverse engineered? This is one of those "curiosity killed the cat" type projects; I've been wanting to use the HP LA inverse assemblers on a PC since I got my 1651B (mainly because a PC can theoretically handle a much larger symbol table). Writing an assembler / compiler for my own custom format and VM is always an option, I suppose, but I'd rather like to be able to run the HP IAs that I don't have the source code for (ISTR I've got a 68000 one somewhere). Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

16 years, 3 months

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Whatever happened to the DG software archive...

by mjkerpan＠kerpan.com

... that was announced by Bruce Ray back in December. The original posting promised details in a few weeks but AFAIK such details never can forward. Did something happen to cancel the deal at the last second or are things just taking longer than originally thought. Mike

16 years, 3 months

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pdp-11 ME11-L core memory system engineering drawings

by hp-fix＠xs4all.nl

I've aquired the pdp-11 ME11-L core memory system engineering drawings. Before I put it on ebay, if some one is interested, contact me off-list. -Rik

16 years, 3 months

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PDP, TYPESET-8 and linotypes

by michaelkraus1969＠yahoo.com

Linotypes, when driven from paper tape, used the 64 bit, six level TTS or Teletypesetter code. There are two key line ending codes that were always in sequence. One was the?RETURN code and the other was the ELEVATE code. ? On the linotype, the ELEVATE key would end the line and "elevate" the matrixes, as a group, to the caster and eventually to the distributor. ? ?

16 years, 3 months

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Dice (was Leaving computers on... (was Re: Disc analyser news update))

by roger.holmes＠microspot.co.uk

On 26 Mar 2010, at 06:00, cctalk-request at classiccmp.org wrote: > > Message: 8 > Date: Thu, 25 Mar 2010 18:58:19 +0000 (GMT) > From: ard at p850ug1.demon.co.uk (Tony Duell) > Subject: Re: OT: Leaving computers on... (was Re: Disc analyser news > update) > To: cctalk at classiccmp.org > Message-ID: <m1NusG5-000J3xC at p850ug1> > Content-Type: text/plain > >> There is a little test jig that is sometimes used, that holds diagonal >> corners of the die between centers, for a spin. If the die reverses >> direction of rotation right before it settles to a stop, then it fails. > > The 'Pviot test for loads'. There are several other ways to make dice > show numbers with the 'wrong' prboabiltiy, though. Six LCD displays, single chip microcomputer and an orientation sensor? :-) Keeps it on topic anyway. > > Totakky OT, byut 'Scarne on Dice' has a couple of chapters on this. (No, > I don't gamble, but I happen to have said book on my bookshelf) > > -tony >

16 years, 3 months

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DECTalk DTC01

by pontus＠Update.UU.SE

Hi All. I've become curious about the different DECTalk devices. There seems to have been a number of variants. The stand alone DTC01, a UNIBUS version and a PCI card version (DTC07). Do all these sound the same? Or are newer ones more advanced? The number (07) on the PCI version indicate that there has been at least seven versions, what are the others? And finally, does anyone have system over and would consider selling it? (DTC01 seems to be the simplest and is thus preferred) Regards, Pontus.

16 years, 3 months

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Desperately Looking for Honeywell DDP-516 documentation

by hachti＠hachti.de

Hi Folks, I recently came across a Honeywell DDP-516 computer. I'm currently resurrecting the system. That basically means assembling the pieces I got and fixing minor issues. The most work comes from missing mounting hardware :-( The system came with a paper tape reader interface. And a paper tape punch interface. I have schematics for the reader interface. --- But I'm desperately looking for the paper tape punch interface schematics! Does anyone have these? Al? Bill? CHM? Someone else? There's also another DDP-516 owner who would like to get hold of these schematics. I have no information about that interface. Only the programming interface is known. And it is not the same interface module as used in the H316. The H316 interface has PTP and PTR in one and uses completely different ?PACs. BTW: I could need some spare ?PACs to fix a memory (so far at least one CM006). Will write a separate post after having checked out the system, listing all I'm looking for. Best wishes, Philipp :-) -- http://www.hachti.de

16 years, 3 months

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Scrapping and re-use (was Re: Talking of old IBM systems)

by ethan.dicks＠gmail.com

On Wed, Mar 24, 2010 at 11:30 AM, Chuck Guzis <cclist at sydex.com> wrote: > On 24 Mar 2010 at 9:16, blstuart at bellsouth.net wrote: > >> I don't know about the ocean, but they did send them off to >> scrap yards and stuff to be demolished... > > There's another aspect to the problem, that CDC ran into during the > 70's--that of used parts finding their way into the mainstream. > Apparently, this was enough of a problem that CDC ordered that any > decommissioned system be reduced to unusable junk... DEC had a problem in the 1980s with parts and machines that had been scrapped ending back in the sales stream. The big problems for them were maintaining the perception of quality (much of what got scrapped had failed some aspect of the testing process) and the tax issue of claiming that an item was scrapped but still out in the world. I was told one source of this was the recyclers picking through the bins of scrap coming from DEC and reselling things that were deemed resellable. They were paying by the pound for precious and ferrous metal scrap but making much more from the occasional gem. As the story goes, DEC bought a large shredder (large enough to accept 19" racks!), ensuring that re-use would not be feasible. We had a similar issue at Software Results - obsolete (prototypes and Rev 0 boards) and unrepairable boards were lying around after they'd been scrapped - we couldn't repair them since they'd been written off, so since they were large and green (because of the solder mask), one of our student employees nailed a bunch of them to a wooden frame in an irregular isosceles triangle pattern and made a "COMBOARD Christmas Tree" (using 9-track write rings as ornaments and tractor-feed tearoffs as garlands). Because the boards were rendered more unusable (as computer peripherals) by drilling nail holes in them, it was considered an acceptable re-use. I wish I had a picture of it still. -ethan

16 years, 3 months

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Laugh, it's funny

by evan＠snarc.net

http://www.theonion.com/articles/computer-company-started-in-garage-30-year…

16 years, 3 months

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MIPS CPUs

by classiccmp＠philpem.me.uk

(Taking this into a separate thread, it has nothing to do with disc analysers). Cameron Kaiser wrote: >> As I understand it, you can design a MIPS chip based on the published >> specs and not have to pay any licensing fees. There was a patent on the >> unaligned load/store instructions, but that expired in 2006 AIUI. > > That's probably why the Chinese have jumped on it (Godson/Loongson), not > that they worry excessively about licensing, but anyway. It's probably why there are so many open-source MIPS cores on Opencores too. I've been playing with UCore this evening and tweaked it to run at about 80MHz on an Altera Cyclone II. Unfortunately the feature list on Opencores is for a newer version of the code, which was apparently never uploaded :( I've got a few 'suspended projects' that would benefit from having a reasonably fast (~100MHz would be nice, ideally with a bit of I-cache and D-cache), 32-bit RISC CPU core with decent compiler/RTOS support. Ucore seems to fit the bill (although there are reports that it doesn't work properly) but the "older version" of the code has support for instruction or data caching :( :( (That and I'll need to rig up some form of bus arbitration scheme to merge the Instruction and Data buses together... now won't that be fun.. at least it's WISHBONE compliant, I suppose) -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

16 years, 3 months

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IBM Monochrome "Black and White" Parallel card double image

by billdeg＠degnanco.com

I am working with an IBM Monochrome "Black and White" Parallel card that is showing a double image. I noticed that the 106 / 16+ tant cap at the top left near where C1 / U47 is printed was broken off the board so I put in a new one. There was no change. I tried another cap, no change. I removed the cap entirely, no change. I am looking for a schematic/docs/suggestions. It looks something like this: ------------------------------------------------- -128K 128K - - - - - - - - - - - - - - - ------------------------------------------------- Thanks.

16 years, 3 months

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IBM Monochrome "Black and White" Parallel card double image

by billdeg＠degnanco.com

>> > This is one of the original black connector versions of the IBM >> > 1904057 XM 407 display cards. It has 9114 RAMs in it, not socketed of >> > course, so I think if I can probe each RAM chip first to ID the bad >> > chip it'd be more efficient. I would similarly have to check the >> > 74L chips. oy! >> > > I know this is a stupid question, but have you scoped the sync > signals from the card? > > --Chuck > > No, I did not. Unfortunately this is not my forte. Bill

16 years, 3 months

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Reusing old floppy *drives*

by lproven＠gmail.com

Noting the discussion on old media, a slightly different question. Please excuse my profound ignorance on matters electronic! I have read, somewhere, that it is possible to connect HD floppy drives to elderly kit that is only expecting DD drives, and use them for just DD operation. More specifically, I'd like to resurrect my ancient Sinclair Spectrum with its MGT DISCiPLE disk interface. Way back in the 1980s, I used 5?" media, as they were still cheaper. However, now, I daresay I won't find any new 5?" media and even 3?" DD media are getting tricky. So what I was considering doing was connecting a pair of old PC floppy drives - 3?" HD (1.4MB) floppies - and quite possibly using 1.4MB media, but only formatting them to 720K and using them as 720K. IIRC, the drives permit this. The track widths are the same - both are 80t drives - it's just that DD used 9 sectors per track and HD 18. Is this likely to work? I realise I'll need to find drives with a unit selection jumper on them, so I can set one as 0 and the other as 1; no twists in the cables this far back, & I'm guessing that a twisted cable wouldn't work with a controller that wasn't expecting it...? -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat/Yahoo/Skype: liamproven ? LiveJournal/Twitter: lproven MSN: lproven at hotmail.com ? ICQ: 73187508

16 years, 3 months

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chemistry simulator on Apple ][?

by adamg＠pobox.com

Dave McGuire wrote: > A local friend is looking for an old chemistry simulator program >for the Apple ][. Here's his description: > >> I'm trying to find a "chemistry simulator" program that I used to play >> with on an Apple II way back in the day. I don't remember the name of >> it, but I remember being able to build a decent "lab" out of parts and >> pieces. I remember that the first lesson was an experiment to figure >> out why the fertilizer ship in Texas City exploded after an onboard >> fire. This was called Chem Lab, and I think it was published by Simon & Schuster. -- Adam

16 years, 3 months

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Wanted: Graphics card and drive sled for RS/6000 7046-B50

by dm561＠torfree.net

Date: Tue, 23 Mar 2010 19:16:50 -0400 From: Sridhar Ayengar <ploopster at gmail.com> Subject: Re: Wanted: Graphics card and drive sled for RS/6000 7046-B50 M H Stein wrote: >> I recently bought an RS/6000 7046-B50. It didn't have a graphics card >> installed (I can use it over a serial console, but I would prefer to be >> able to use a graphical console). It is also missing the drive sleds. >> Does anybody have a graphics card or drive sled that would work with it? > > ---------- > A few days ago I posted here about an RS/6000 available in the Toronto > area but there was no interest either here or elsewhere, so it's being > scrapped on Thursday. > > This is an RS/6000 Power Server 520, Type 7013, Model# 26-10855; > If it has a graphics card would it fit in yours and what would the number be? > And are the sleds compatible? Neither would be compatible. Peace... Sridhar ------------------------------ Thanks for that info, Sridhar; I googled the 7046 and yes, it looks like it's at least ten years newer than mine which I think is one of the very first RS/6000s, and a completely different machine; too bad. mike

16 years, 3 months

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Leaving computers on... (was Re: Disc analyser news update)

by pcoghlan+cctech＠vms.eurokom.ie

> >Another very common one is that the startup resistor of a switch-mode PSU >goes open-circuit while the machine is left on The PSU keeps working as >long as the mains is there, but if it gets turned off, or the mains >fails, of course it won't restart. > >Some terminal servers and the like were very prone to this problem. > >It's a very easy fix once you know which resistor to check. > I've had a slightly related fault in the switch-mode power supply (wall wart) of a Decserver 90 terminal server. A small electrolytic smoothing the supply from the startup resistor had lost capacitance. Lisening closely to the power supply, I could hear a high pitched whine which made me think there was a good chance this was normal vibration of the chopper transformer and threw me right off finding the real problem. When the capacitor was replaced, the whine went away and the power supply worked correctly, for a few weeks before it failed again. I haven't had the heart to investigate further. Regarding Dec equipment, recent experiences are making me speculate that leaving some items turned off for a few months might be bad for them! - An Alpha 3000/300 in continuous use for several years was retired. When I next turned it on several months later, it gave a loud bang and emitted smoke from the PSU. This turned out to be from a VDR which had exploded due to a triac shorting. (This wasn't easy to track down as the VDR had been sleeved with rubber which completely hid the problem.) The function of the triac was to automatically switch between 115V and 230V input. Its shorting left the PSU permanently in 115V mode and the power around here is 230V. Replacing the VDR (after a good bit of fun tracking down a suitable replacement) and snipping out the triac (which I couldn't find a replacement for) solved the problem at the expense of being able to operate on a 115V supply. - A HSZ80 disk controller, like the 3000/300, also failed with a loud bang, without smoke though, making it difficult to figure out which of the many items plugged into the extension lead had blown the house fuse this time. An unmarked item across the mains which looks like a VDR or disc capacitor had shorted. I can't replace it as I have no idea what its spec is. - A Vaxstation 3100, also in continuous use for several years was similarly retired. In service, it had suffered very occasional memory failures but nothing persistent. When I switched it on a few months later, several problems were apparant. Firstly, one of the fans in the PSU ran for a short while and seized. Secondly, the memory power-on test failed to complete. It didn't report an error but the machine reset in the middle of the test and went back to the beginning of the power-on tests in an infinte loop. It's not supposed to do that! Removing both 4MB memory expansion boards got past that problem but resulted in a horrible error from the SCSI driver on attempting to boot, presumably because there was not enough memory on the motherboard. Replacing one memory board (either one!) got by this problem but it then became apparant that the disk was failing with lots of clunking and clicking and various errors reported. Finally, the "compose" light on the keyboard remains lit all the time which as far as I recall may be intended to indicate that all is not well in some part of the system in the event that nothing appears on the graphics console. - A Microvax 3100 model 80 retired for some years was quite happy to perform correctly for a few hours when switched back on. However, after later shutting down and restarting, it died in the middle of the memory test and produced no console output since. It's been a while since I looked at it and I can't remember what indication the diagnostic leds gave. I'm sure if they gave any useful lead I would have followed it up though. Sometime I feel like my kit is failing quicker than I can get around to fixing it. Regards, Peter.

16 years, 3 months

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IBM 7374 and HP Draftmaster II info needed

by starbase89＠gmail.com

I am trying to dig up information on these two plotters to make them more sellable. They are among the flotsam amassed by Infoage, and just take up space. Thanks Joe

16 years, 3 months

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semi-OT: do you routinely attempt projects out of your comfort zone?

by keithvz＠verizon.net

Do you routinely attempt projects out of your comfort zone? While I think it is the right thing to do intellectually to expand my knowledge, I often think that I waste a lot of time trying to do fairly simple tasks in areas where I have limited knowledge or experience. I think challenges can be rewarding, and I enjoy them. "Anything worth doing is hard." I think is the phrase. I try to do the necessary research, background reading, start from the ground up before attempting to do anything. I still find that getting your hands in it, ie learning by doing, seems to help the process along. With all this being said, it sure is frustrating and the rewards come slowly. While I DO like instant gratification, I don't expect it. I do expect that the payoff, it terms of reward vs time spent is reasonable. As my available personal free time has been less and less lately, making sure that I'm not just wasting my time is important to me. Do you find that you spend most of your time on projects that are well within your knowledge and experience, or most of your time learning about new technology/skills/programming language/hardware/etc to facilitate accomplishing a new project? Thanks Keith

16 years, 3 months

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Async logic

by trag＠io.com

> > Date: Tue, 23 Mar 2010 08:31:13 -0700 > From: Al Kossow <aek at bitsavers.org> > On 3/23/10 4:09 AM, Julian Skidmore wrote: >> >> Alexey Toptygin wrote: >> >>> What's wrong with pulse or async logic designs? I personally find them >>> fascinating, but I've never gotten to play with an implementation of >>> one... Are there problems with designing like this that made people >>> switch >>> to sync designs? Anyone know of any good books on non-synchronous logic >>> design? >> >> Probably the best resources are the Amulet resources from Manchester >> University. >> > > Or the work on logical effort by Ivan Sutherland. I did some contract design work for a company called Theseus (Mumble) back around 2000. Their stuff was all non-clocked logic. They used two rails per bit and depending on how the two rails were coded it represented either 0, 1 or ready (or finished?), if I remember correctly. The logic to signal back the completion and readys about doubled the amount of real estate the logic used, but it could run as fast as the gates allowed, did not have a synchronizing pulse, making remote monitoring attacks difficult to impossible and only used as much power as it needed to process the actual data available. The amount of design discipline needed was substantial, making me wonder if just going to the trouble of implementing more traditional power saving techniques wasn't a better option. Jeff Walther

16 years, 3 months

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The Oldest Toshiba Laptop in Portugal

by billdeg＠degnanco.com

There's a contest with a prize of a new Toshiba laptop that goes to the person with the oldest working Toshiba laptop: http://www.facebook.com/toshibaportugal?v=app_7146470109 (it's in Portuguese). You must be a Portuguese citizen. Bill

16 years, 3 months

1
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Leaving computers on...

by bqt＠softjar.se

"Jeremy S. Sharp" <theodric at gmail.com> wrote: > Is there anybody here who keeps classic big(-ish) iron running 24x7? > I've been told a story of a burning PDP-11/34 which has somewhat put > me off any notion of leaving my -8s turned on when I'm not within > reach of a killswitch & fire extinguisher. :) At the moment, nothing more than my 11/93. Current uptime about a month. I used to manage an 11/70 as well. It's still on standby, but powered down most of the time right now because of cooling problems, and electricity bill. (Same with a VAX-8650.) Johnny

16 years, 3 months

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Wanted: Graphics card and drive sled for RS/6000 7046-B50

by dm561＠torfree.net

Date: Mon, 22 Mar 2010 18:04:26 -0600 From: Andrew Warkentin <andreww591 at gmail.com> Subject: Wanted: Graphics card and drive sled for RS/6000 7046-B50 >I recently bought an RS/6000 7046-B50. It didn't have a graphics card >installed (I can use it over a serial console, but I would prefer to be >able to use a graphical console). It is also missing the drive sleds. >Does anybody have a graphics card or drive sled that would work with it? ---------- A few days ago I posted here about an RS/6000 available in the Toronto area but there was no interest either here or elsewhere, so it's being scrapped on Thursday. This is an RS/6000 Power Server 520, Type 7013, Model# 26-10855; If it has a graphics card would it fit in yours and what would the number be? And are the sleds compatible? mike

16 years, 3 months

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[BBC-Micro] Re-using floppies

by pete＠dunnington.plus.com

On 22/03/2010 19:18, Alex Taylor wrote: > The idea was that reformatting a 1.44MB HD disk in a DD drive will > leave traces of the original formatting behind (as they're always > preformatted for DOS/Windows), causing the unreliability. Using a bulk > eraser is meant to eliminate this problem, as it will turn them into > completely blank disks that can be formatted in a DD drive more > reliably. That won't really matter. When you format a disk you write bit patterns all over it: in the headers, in the data sectors, and even in much of the gaps between them (sync bytes and clock patterns used as markers). Thus there's something there even when you write the first real data, and of course it never lines up exactly, bit for bit. Therefore you still have the problem of interference from the previous "data" even if it's just the dummy data used to fill a "blank" sector, and the sync bytes and markers in the preamble to it. -- Pete Peter Turnbull Network Manager University of York

16 years, 3 months

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cctalk Digest, Vol 79, Issue 44

by alhartman＠yahoo.com

I don't know what the market is like in Europe, but I can still buy new media in 5.25" and 3.5" format easily here in the U.S. Google brings up many places here. If there are no such outlets in the UK, maybe you can get a bulk order together with some local folks to save on the shipping costs? Al From: Liam Proven <lproven at gmail.com> Subject: Reusing old floppy *drives* Noting the discussion on old media, a slightly different question. Please excuse my profound ignorance on matters electronic! I have read, somewhere, that it is possible to connect HD floppy drives to elderly kit that is only expecting DD drives, and use them for just DD operation. More specifically, I'd like to resurrect my ancient Sinclair Spectrum with its MGT DISCiPLE disk interface. Way back in the 1980s, I used 5?" media, as they were still cheaper. However, now, I daresay I won't find any new 5?" media and even 3?" DD media are getting tricky. So what I was considering doing was connecting a pair of old PC floppy drives - 3?" HD (1.4MB) floppies - and quite possibly using 1.4MB media, but only formatting them to 720K and using them as 720K. IIRC, the drives permit this. The track widths are the same - both are 80t drives - it's just that DD used 9 sectors per track and HD 18. Is this likely to work? I realise I'll need to find drives with a unit selection jumper on them, so I can set one as 0 and the other as 1; no twists in the cables this far back, & I'm guessing that a twisted cable wouldn't work with a controller that wasn't expecting it...? -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat/Yahoo/Skype: liamproven ? LiveJournal/Twitter: lproven MSN: lproven at hotmail.com ? ICQ: 73187508

16 years, 3 months

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Tektronix manuals available

by auringer＠tds.net

Hello, I have the following Tek Instruction Manuals sitting here. I would like to free up the space they are consuming. If someone wants to make it worth my while to spend the time shipping them out, I will entertain offers. Otherwise, I will dump them in the recycling. Preference will go to the fewest number of boxes I have to deal with and, of course, compensation offered. I will accept offers until Sunday (28th) evening. I will ship or recycle Monday. Shipping from 53714. Jon -- 7904 Oscilloscope operators 7904 Oscilloscope Service 7A13 Differential Comparator 7A19 Amplifier 7A26 Dual Trace Amplifier 7B92A Dual Time Base 7B80 Time Base 7B85 Delaying Time Base 7M11 50-Ohm Delay Line S-6 Sampling Head S-52 Pulse Generator Head S-53 Trigger Recognizer Head C-5C Camera 2215 Oscilloscope Service P6056/P6057 Probe P6131 Passive Probe P6460 Data Acquisition Probe K212 Portable Instrument Cart 1240 Workbook I also have "data sheets" for the following items: P6063B Passive Probe 200C Scope-Mobile Cart

16 years, 3 months

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mewel

by mcl198＠frontiernet.net

Hello, Does anybody have the source code and libarays for the old MEWEL windows interface? I have been looking for this so the source code for a Juki Pick and Place machine can be updated. If there is a fee for this, just let me know. Thanks, Patrick McLeod McLeod Instruments, Ltd. 928-535-6369

16 years, 3 months

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Async logic

by julianskidmore＠yahoo.com

Alexey Toptygin wrote: > What's wrong with pulse or async logic designs? I personally find them > fascinating, but I've never gotten to play with an implementation of > one... Are there problems with designing like this that made people switch > to sync designs? Anyone know of any good books on non-synchronous logic > design? Probably the best resources are the Amulet resources from Manchester University. http://intranet.cs.man.ac.uk/apt/async/ In the late 90s they experimented with Asynchronous ARM processors. The difficulty with asynchronous design is that it's far more prone to race hazards than synchronous design. Also, they found that even the simple handshaking protocol they used limits performance. Nevertheless, they do have some advantages, for example their EMF emmissions tend to be evenly spread across a broad spectrum. Incidently, modern synchronous design is far less synchronous than it used to be; high clock rates mean that CPUs are subdivided into differently clocked domains to avoid clock skew. -cheers from julz @p

16 years, 3 months

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eBay Oz : Collection of DEC Unibus modules including custom wire-wrap

by unibus＠gmail.com

> > Message: 6 > Date: Tue, 16 Mar 2010 20:12:10 +1100 > From: Nigel Williams <nigel.d.williams at gmail.com> > Subject: eBay Oz : Collection of DEC Unibus modules including custom > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > All sorts of interesting items: TU-60, CM-11, M792 etc > > http://shop.ebay.com.au/pdp11.caps11/m.html?_nkw=&_armrs=1 > > not connected with seller, however I did purchase fanfold paper-tape from > this eBayer. > I'm the seller so blame me.... blatant plug follows :-) I have to clear out my shed so I'll be dumping on eBay.com.au various bits and pieces. Predominantly it will be DEC UNIBUS modules, papertape, CAPS-11 operating system, plus technical documentation. Stuff is coming out in random order. E.g. some of the -K series laboratory modules have been listed but I've only just found the panels and some of the cables. Really only of interest to Australians are the heavy/bulky/delicate items like the PDP-11 system with the LPS-11 / TU60, or FABRI-TEK Model 11 Add-On Memory System, etc., that are being listed as local pickup. There will some Heathkit (H10 papertape readers/punches and a 3400A microcomputer trainer) plus should be some HP GPIB gear. The Tektronix gear has already gone. I do not have any CM-11 card readers, just some of the UNIBUS interface modules. Regards, Garry

16 years, 3 months

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Wanted: Graphics card and drive sled for RS/6000 7046-B50

by andreww591＠gmail.com

I recently bought an RS/6000 7046-B50. It didn't have a graphics card installed (I can use it over a serial console, but I would prefer to be able to use a graphical console). It is also missing the drive sleds. Does anybody have a graphics card or drive sled that would work with it?

16 years, 3 months

1
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chemistry simulator on Apple ][?

by mcguire＠neurotica.com

A local friend is looking for an old chemistry simulator program for the Apple ][. Here's his description: > I'm trying to find a "chemistry simulator" program that I used to play > with on an Apple II way back in the day. I don't remember the name of > it, but I remember being able to build a decent "lab" out of parts and > pieces. I remember that the first lesson was an experiment to figure > out why the fertilizer ship in Texas City exploded after an onboard > fire. Does anyone know what this might've been called, or better yet, does anyone have a copy? -Dave -- Dave McGuire Port Charlotte, FL

16 years, 3 months

1
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Taking offers on PDP-8 (straight-8)

by sellam＠vintagetech.com

A straight-8 has come up for sale. I am representing the seller. I have photos and details. If you're interested please e-mail me and I'll send over some information. Preliminary photos are here: http://siconic.com/computers/PDP-8/ We'll take opening offers and if there's one good enough then we'll cut to a straigt (8) sale. Otherwise, it'll move on to a VCF web auction at a future date. Thanks!! -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

16 years, 3 months

14
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HP 2671 Graphics ROM

by hp-fix＠xs4all.nl

I aquired a HP 2671A thermal printer and know that there should be an upgrade ROM to 'upgrade' it to a HP 2671G. Thanks to Tony excelent work on HPCC CDROM i have the schematics and was able to fix the head positioning circuit. One of the driver transistors (TIP 122) was bad after replacing it and cleaning the printer it works fine. But now I want to use it for printing graphics (diagrams) and would be very happy whith an image of the graphics ROM. -Rik PS. don't shoot me if it appears a second time, I used the first time the wrong email address.......:-(

16 years, 3 months

2
9
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HP 2671 Graphics ROM

by nig.bailey＠virgin.net

I don't know where you are tony, but I have the right pod on my old stag to do 80/8749s I'm in luton.

16 years, 3 months

3
2
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RGB-VGA Converter -- buy or build?

by stojoskij＠ikomline.net

Hi, I need scematics of RGB to VGA converter. I want to connect Wheel Balancer machine to computer VGA monitor. Old monitor is VALVO VCC93/00 fixed frequency (15KHz) and have R, G, B and common Sync signals. I would be grateful if you can help me! Best regards, Jovica

16 years, 3 months

8
18
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Disc analyser news update

by jonas＠otter.se

On Sat, 20 Mar 2010 20:38:31 +0000 (GMT), ard at p850ug1.demon.co.uk (Tony Duell) wrote: > Subject: Re: Disc analyser news update > To: cctalk at classiccmp.org > Message-ID: <m1Nt5RK-000J3oC at p850ug1> > Content-Type: text/plain > ... > > Well, OK, please name one change in the last 20 years that has made > _my_ > life better. > > -tony > I don't know what your health is like, but should you get high blood pressure, or a hernia, I can assure you that the medicine/surgery you will get will be much better than what was available 20 years ago. Or even having some procedure done by a dentist. And personally, I find that modern mobile phones and new services available on the Internet (on-line banking, for example) have made *my* life a lot easier (and better). /Jonas

16 years, 3 months

2
1
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HP equivalents lists -- warning!

by ard＠p850ug1.demon.co.uk

I am sure everyone here who fixes old HP stuff knows of the equivalents lists that were published in Bench Briefs (which are now on the web). Today I was looking at aboard from an HP tape drive. I was pretty sure the 40 pin chip with a Motorola logo and an HP 1820-xxxx number was some flavour of 6809, but I couldn't rememebr what speed of whether it was an -E version, so I grabbed the latest equivalent list. I wasn't listed... But I was sure I recognised the number, so I looked in my older list. It was there. A 68B09. I also found a device I was looking at the other day, and which I suspected was a microcontroller (and isn't in the latest list) is listed in the older one as a 68488 ()which is what I deduced it to be after spending several hours downloading data sheets from the web and trying to match up pinouts). Argh! So a warning : Devices are sometimes removed from this equivalents list. You need to check all of them to see if it's listed anywhere. -tony

16 years, 3 months

1
0
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Help with running RT-11 SAV files under RSTS/E

by jhfinedp3k＠compsys.to

I have been interested, of late, in fixing some of the bugs in MACRO.SAV / CREF.SAV which the documentation shows also run under RSTS/E. In addition to fixing the bug so that the year outputs as 4 digits on the listing, I thought it would be interesting to run MACRO.SAV as a system job. This requires a mapped RT-11 monitor to use VBGEXE.SAV to load and initiate MACRO.SAV since it is obviously not an REL file. However, the goal is to still be compatible running under RSTS/E. My question is how to distinguish between a mapped RT-11 monitor and RSTS/E? Does anyone have sufficient information about the RSTS/E environment to be able to distinguish RT-11 from RSTS/E? TSX-PLUS is trivial since requesting the TSX-PLUS job number is not supported under RT-11, so that problem is solved. Jerome Fine

16 years, 3 months

2
10
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Solid State Disk replacement for RD53, 54, RK05, RL02/02

by emu＠e-bbes.com

Rob Jarratt wrote: > There was a thread recently on the comp.sys.dec newsgroup which ended up > with the suggestion from David Riley that he would be prepared to build an > FPGA-based board with a QBUS interface on one side and an SD interface on Is there really still interest in it ? I put my design away few years ago, as I didn't see anybody interested enough to buy one. There is the seasonal talk of it for sure, but ... OTOH, they old ones show up on ebay frequently, and they are not that expensive. Remarks ? Cheers

16 years, 3 months

9
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