test-drb January 2008

test-drb@ccmp.vtda.org

221 participants
430 discussions

by ljw-cctech＠ljw.me.uk

I've just had a email from Bob Doran, who was one of my CompSci professors at Auckland University. It seems that they (AU Comp Sci) have the front panel from my 360 which they salvaged many years ago, and which is now becoming part of a lobby display. So at least now I know something about what happened to it, but I suspect that the rest of the system was scrapped. One part he's after for the panel is the centre Display Store Selection rotary switch dials (there are two parts to the rotary switch), so if anyone happens to know where there's a spare one, I'm sure he'd be grateful! (See the top picture at http://www.corestore.org/360.htm , thanks Mike!) -- Lawrence Wilkinson lawrence at ljw.me.uk The IBM 360/30 page http://www.ljw.me.uk/ibm360

18 years, 1 month

Who's collection is that?

by sellam＠vintagetech.com

View the YouTube clip on this blog posting by Christine Finn: http://blog.wired.com/underwire/2008/01/top-gear-star-i.html This is Jeremy Clarkson, some British guy who does a show called "Top Gear". I'm not familiar with it. But what I want to know is, whose collection is that in the video? And why did they allow this psychotic monkey to start going apeshit with a hammer around all those vintage machines? -- 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 ]

18 years, 1 month

Keyboard PS/2 to Parallel converter

by elazzerini＠interfree.it

I report each part of different emails whit my question: From: "Roy J. Tellason" <rtellason at verizon.net> There was some project article in Byte way back when, by Steve Ciarcia, which provided a peecee-type keyboard input (AT rather than PS/2 but that shouldn't make that much difference). The circuit to deal with this was very simple and elegant, though I can't remember any more just how it was done. He didn't use a UART or similar, though, just a couple of MSI chips. And I remember thinking then how it wouldn't be all that hard to stuff an eprom between the output of that circuit (which gave you keycodes rather than characters) and have it spit out ASCII. Perhaps one of these days I'll run across the article again. Roy, here would be the list of articles by Steve Ciarcia http://www.devili.iki.fi/library/author/203.en.html May you try to find the exact article? Enrico From: "Dave Dunfield" <dave06a at dunfield.com> If anyone is interested, I have a very small bit of 8051 code which reads an attached PC keyboard, providing the scan codes over an RS-232 link. It also supports commands to set LEDs on/off etc. I specifically avoided using the P1 line in my design (full 8-bits parallel I/O available even on an 8031), so these are free, making it very trivial to modify this to output parallel instead of serial - it would also be very easy to add a translate table and recognition of shift/ctrl modifiers so that it would output fully decided ASCII. Dave , have you just the code or even the circuit PCB layout? And have you an idea to how to transform the circuit from serial to parallel? Enrico From: Jim Brain <brain at jbrain.com> If you didn't care about sending codes back to the keyboard, then you'd just need an 11 bit shift register. The previously mentioned <http://eece.ksu.edu/~eece696/beta/digital/A/stop.htm> http://eece.ksu.edu/~eece696/beta/digital/A/stop.htm is almost there, it just needs 1 more F/F 2 LS174s would work for the F/Fs. the CLK line needs to be inverted, but you can probably get away without doing it. A divide by 11 counter (LS163 with and AND on bit 0,1 and 3 driving CLR) should do the trick. Jim, i need just this, I don't care to see the caps lock led turning on or off!! But the schematic indicated to that link, it appear to be a theoric schematic. I really have not time to testing circuit or verify how it works. So anybody has an idea of a pratical circuit working? Thanks Enrico From: Holger Veit <holger.veit at iais.fraunhofer.de> No, I am not yet at a point to use a microcontroller just to blink a LED, which have been done with two cross coupled transistors in the past, but a PIC is meanwhile the more compact, easier, more flexible solution to "convert-from-A-to-B" problems. Holger, it's exactly what i'm looking for. So may you give your help? What PIC to use? I have a PS2 Keyboard and when I press the character A I need to have the binary code 41H that means 0100 0001B on eight wires plus a strobe line. Only in this direction. Is it possible? Thanks Enrico

18 years, 1 month

Keyboard PS/2 to Parallel converter

by ajp166＠bellatlantic.net

> >Subject: Re: Keyboard PS/2 to Parallel converter > From: "Dave Dunfield" <dave06a at dunfield.com> > Date: Mon, 07 Jan 2008 19:51:21 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> > Date: Mon, 7 Jan 2008 08:54:38 -0800 (PST) >> > From: Fred Cisin <cisin at xenosoft.com> >> >> > It would seem that the cheapest way to do it is a discardable PC. >> > >> > Input character >> > print it >> > loop Not cheap and noisy. You could yank the 8042 used in 386 through early P1 boards as the first level interface. But that does not translate the scan code to ASCII serial or parallel wich is what most people would like. >> Only barely possibly the cheapest. A $2 PIC or AVR or even 8051- >> family chip can do the same job for a fraction of the power and space >> and noise. And the code is out there--I've seen code for getting >> PS/2 keyboard data into both PICs and AVRs. The output side would be >> a piece of soup. Absolutely. Even an 8048 (8035 or 8748) pull from a older keyboard is more than enough CPU for the job. The DEC LK20X (30x/40x) series keyboards used an 8051, pull the EA line high and it's a 8031 (add a latch and external rom). >> >> And a PIC could be considered "retro"; certainly an 8051 would be. >> Both are descended from mid-70's chip designs. >> >> But to answer an earlier question--no, a simple serial-in, parallel- >> out shift register won't do the job with a PS/2 keyboard--the >> interface has a bidirectional protocol--it just doesn't blindly send >> out scan codes. > >If anyone is interested, I have a very small bit of 8051 code which reads an attached PC keyboard, >providing the scan codes over an RS-232 link. It also supports commands to set LEDs on/off etc. I'd be interested. PS2 in and ASCII serial (or parallel with strobe, output only) out is most useful in vintage designs. Most vintage machines do not need bidirectional control but the local CPU (8051) would have to echo the state of the NUM and shiftlock keys to the LEDs and do code conversion accordingly. Allison > >I specifically avoided using the P1 line in my design (full 8-bits >parallel I/O available even on an 8031), so these are free, making it very trivial to modify this >to output parallel instead of serial - it >would also be very easy to add a translate table and recognition of >shift/ctrl modifiers so that it would output fully decided ASCII. > > >Dave > > >-- >dave06a (at) Dave Dunfield >dunfield (dot) Firmware development services & tools: www.dunfield.com >com Collector of vintage computing equipment: > http://www.classiccmp.org/dunfield/index.html

18 years, 1 month

Keyboard PS/2 to Parallel converter

by ajp166＠bellatlantic.net

> >Subject: Re: Keyboard PS/2 to Parallel converter > From: "Roy J. Tellason" <rtellason at verizon.net> > Date: Mon, 07 Jan 2008 18:51:24 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Monday 07 January 2008 11:54, Fred Cisin wrote: >> It would seem that the cheapest way to do it is a discardable PC. >> >> Input character >> print it >> loop > >There was some project article in Byte way back when, by Steve Ciarcia, >which provided a peecee-type keyboard input (AT rather than PS/2 but that >shouldn't make that much difference). The circuit to deal with this was very >simple and elegant, though I can't remember any more just how it was done. It used a Z80 and a PPI rom and ram. At the time that was a easy small design but still far more cpu than needed. The task is PIC or 8048 sized. Fornm the At days to current the PS2 keyboard is handled with an 8042 (discrete or embedded) which is a slave bus verion of the 8048.. There are PIC designs for this out there as well as Atmel ATmega. Check their sites. >He didn't use a UART or similar, though, just a couple of MSI chips. And I >remember thinking then how it wouldn't be all that hard to stuff an eprom >between the output of that circuit (which gave you keycodes rather than >characters) and have it spit out ASCII. Ah, you do you handle the key down codes and the key up codes? > >Perhaps one of these days I'll run across the article again. I have it burried somewhere. It does not translate well to an PS2 keyboard as the XT keyboard used for that has slower IO rate and different keyscan. It would be a pain to do in simple logic as you need at least a state machine. Allison >-- >Member of the toughest, meanest, deadliest, most unrelenting -- and >ablest -- form of life in this section of space, ?a critter that can >be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" >- >Information is more dangerous than cannon to a society ruled by lies. --James >M Dakin

18 years, 1 month

Wonder how useful this would be, MMC to floppy disk adapter

by bob099＠centurytel.net

http://www.flash-memory-store.com/clearance-flashpath-mmc-floppy-disk-adapt… The FlashPath is a floppy disk adapter that lets you read and write data to your MultiMedia Card (MMC) using your computer's floppy disk drive. Sale Price $9.99

18 years, 1 month

Can anyone ID this computer from the 80s?

by tosteve＠yahoo.com

On the right, is it a computer, or just a dumb terminal? There's a printer and possibly floppies in the background, but where do they go? http://oldcomputers.net/temp/1980something.jpg Thanks- Steve. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.

18 years, 1 month

Keyboard PS/2 to Parallel converter

by cclist＠sydex.com

> Date: Mon, 7 Jan 2008 08:54:38 -0800 (PST) > From: Fred Cisin <cisin at xenosoft.com> > It would seem that the cheapest way to do it is a discardable PC. > > Input character > print it > loop Only barely possibly the cheapest. A $2 PIC or AVR or even 8051- family chip can do the same job for a fraction of the power and space and noise. And the code is out there--I've seen code for getting PS/2 keyboard data into both PICs and AVRs. The output side would be a piece of soup. And a PIC could be considered "retro"; certainly an 8051 would be. Both are descended from mid-70's chip designs. But to answer an earlier question--no, a simple serial-in, parallel- out shift register won't do the job with a PS/2 keyboard--the interface has a bidirectional protocol--it just doesn't blindly send out scan codes. Cheers, Chuck

18 years, 1 month

help GridPad 2050SL

by bob099＠centurytel.net

I just pulled my GridPad 2050SL out of the garage, fired it up, and it worked fine, for about 15 minutes. Then the screen started to fade, adjusted contrast and brightness, worked for a few minutes then nothing, just the backlight. Let it set for a few minutes, it fired up, but quickly back to the blank screen, with a quicker fade. Any suggestions on what to check? It has been in storage for the past 4 years, no climate control, so anything is possible. Probably heat related component failure or solder joint, but where to look. Nothing found on the web.

18 years, 1 month

Keyboard PS/2 to Parallel converter

by elazzerini＠interfree.it

But to answer an earlier question--no, a simple serial-in, parallel- out shift register won't do the job with a PS/2 keyboard--the interface has a bidirectional protocol--it just doesn't blindly send out scan codes. Cheers, Chuck And then anybody has suggestion for a READY to USE black box? Input PS/2 Output D0 to D7 + Strobe signals Thank to all that will have all useful suggestions. Enrico

18 years, 1 month

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test-drb January 2008