test-drb February 2008

test-drb@ccmp.vtda.org

236 participants
373 discussions

GAL16V8 as a modern substitute for a 7447?

by ethan.dicks＠usap.gov

Hi, all, Has anyone here worked with or ever plotted silently to create a moderish 7-segment decoder/driver from a GAL16V8? I'm working on a project made >from classic parts, and am trying to reduce part count rather aggresively, since I'm going to hand-wire it. One thought was to attempt to combine a 7490 _and_ a 7447 in a single GAL16V8. I have blown hundreds of PALs, but have much less experience in designing with them, so I'm not even sure that it's possible to mash together that much logic internally in a 16V8. I know all the outputs are optionally registered, so presuming one has 4 assignable flip-flops, one could theoretically make a counter on the output pins, but what's less clear to me is if you could then take those terms and internally decode them to a 7-segment display. After the large amounts of replies about this 8-way digital switch, I don't necessarily want to clog the list with discissions of what is and isn't possible for a GAL16V8, so if you can remember, please make any suggestions and comments to me directly, not the list. Thanks for any nudges towards a solution. -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 8-Dec-2007 at 15:40 Z South Pole Station PSC 468 Box 400 Temp -25.4 F (-31.9 C) Windchill -52.5 F (-47.0 C) APO AP 96598 Wind 13.7 kts Grid 12 Barometer 678.8 mb (10674 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html

16 years, 9 months

1st stage loader for IMSAI - need ascii to binary conversion

by jefferwin＠gmail.com

I am in the process of rebuilding an IMSAI 8080 and am using my Mac Pro as a dumb terminal. I have it all to the point where I can type a character and see the ascii appear on the front panel. What I need to do is write a simple 1st stage loader that will take the HEX output from the ASM80 assembler, send it over the serial connection and put it in memory. This way I can write a more sophisticated loader and not have to key it in by hand. The question is, what is the algorithm, in assembly language, for converting an ascii character to its binary equivalent. By this, I mean converting an 'a' to 1010, not 041H which is the ascii value. I remember writing such a thing 30 years ago but simply cannot get my head around it now. The algorithm has to deal with taking an ascii string like AF67DBFF6FF9AF81C2130053DBFF5FAAC2210039D20600780747D3FFAF4 and converting each ascii character into the binary value it represents. The sting above would convert, one character at a time, to: 1010 1111 0110 0111 1101 well, you get the point...It has to work only for 0-9 and A-F which should make it easier. Anyone out there remember how to do this? Jeff Erwin

16 years, 9 months

old monitors

by rtellason＠verizon.net

A guy is offering me a pile of old monitors, he describes as "mono, cga and ega", probably about a dozen or so altogether, and presumably all working. I don't have anything that currently uses any of these interfaces running at the moment. Any interest in anybody taking these off my hands? -- 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

16 years, 9 months

HP 87 computer/calculator?

by dbetz＠xlisper.com

When I was at the VCF in Mountain View this past fall, someone in the concessions area had an HP 87 computer/calculator for sale. Does anyone remember who that was? I find I'm getting interested in the HP 8x series. Thanks! David Betz

16 years, 9 months

Q-bus to CF [was: IOmega]

by ajp166＠bellatlantic.net

> >Subject: Re: Q-bus to CF [was: IOmega] > From: der Mouse <mouse at Rodents.Montreal.QC.CA> > Date: Fri, 29 Feb 2008 02:00:53 -0500 (EST) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> Generally IDE and CF (compactflash) are the same interface and for >> Qbus-11 fairly simple. It's been done, however, the problem is the >> driver as bare IDE or CF is NOT MSCP not is it DL, DX, DY or RK so a >> driver is needed and noone has apparently stepped up to do it. > >Not quite true. > >Some time back (years), someone was working on an IDE interface for a >Qbus MicroVAX and I was doing the driver. (This was not bootable; the >idea was to netboot to get the kernel onto the machine.) > >We never got it working, and it is not clear to me, now, why not. I'm >not sure whether this is because it wasn't clear why then or because my >wetware memory has bitrotted - what memory I have indicates that there >were hardware issues, but I had no physical access to the hardware, so >I'm not sure that that's right even aside from bitrotted memory. the likely reason is PDP-11 and VAX does read before write and IDE does not like that. The fis is to make the READ address different >from the write addresses, even DEC did that with interfaces. It is otherwise straightfoward with the usual observance for timing and the like. Allison >I once was one of two people who built a one-off Qbus board out of >wirewrap, so I feel I ought to be able to build such a thing myself. >Perhaps someday I'll gather the parts and try it. (Anyone have a Qbus >development board looking for a home? :) > >/~\ The ASCII der Mouse >\ / Ribbon Campaign > X Against HTML mouse at rodents.montreal.qc.ca >/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

16 years, 9 months

Any word on OS/2 for PDP-11?

by tshoppa＠wmata.com

Dan Gahlinger wrote: > There *IS* a Vax named a "Saul" or "SOL", I've seen it. > It's a "luggable" (so to speak) like the Rainbow, but it's a Vax. > They existed, so don't insult my intelligence. > And btw I've been doing Vaxen since 1976, so I think > I know a thing or two about reading Ascii > it's definitely "OS/2" I think it's time for me to unsubscribe from this list and get back to reality. Sure, let's make up names for already existing products instead of figuring out what they are (VS2000? VAXmate?) and then insist that that we've been doing the VAX a year before it left the factory, therefore OS/2 has to exist for the PDP-11. Why do I even try to interject myself into this crap. Tim.

16 years, 9 months

HP 85 tapes / TU58 tapes

by Mick.Lindell＠ge.com

Greetings, Do you still have the TU58 tapes? Mick Lindell Sr. Test Development Engineer GE Aviation Digital Systems T +1 616 241-8454 E Mick.Lindell at ge.com 3290 Patterson Ave. SE Grand Rapids, MI 49512 USA GE imagination at work These commodities/technical data are controlled for export by the U.S. State Department. They may not be transferred, transshipped on a non-continuous voyage, or otherwise be disposed of outside of the United States, either in their original form or after being incorporated into other end-items, without prior written approval of the U.S. Department of State.

16 years, 9 months

On interfaces, paper tape readers/punches, and single (small) chip micros

by tsw-cc＠johana.com

As said before, one can easily get some of the small (8 pin dip) micros to do magic things, but sometimes (as mentioned) it is a bit more trouble than it is worth. Many of us (me!) have stuff in their junk boxes^H^H^H^H^H^H^H^H^H^Hclassic part archive that will do the task quite easily. In my case, I obtained a nice Facit 4070 paper tape punch and made up a simple interface adapter (it fit inside one of those 2x DB-25 scramble boxes) to make it function using a PeeCee parallel port. Now if I desire to punch a paper tape, all I do is a simple copy to the printer port and ...buzzzz... out comes the tape. Thankfully the Facit 4070 had some power available on its DB-25, but I needed to play around with all the levels (it used 6 volt levels). In the end, all it took was a single 74LS00 to do the trick on changing the strobes to conform. I suppose I could have used an 8 pin ATMEL chip, but why bother. Sometimes the "classic" solution is MUCH easier. I even built up a character font (5x8) so I could punch titles in the tape. Of course, now I need to get the reader functional, but that is another story. p.s. If anyone wants details on the interface, contact me off list. -- Sorry, No signature at the moment. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

16 years, 9 months

front panel display for a modern PC

by slawmaster＠gmail.com

I'd really like to have something like one of the old mainframe/minicomputer control panels for my PC, but I'm just not sure how to implement it. Anybody here tried something like that? Ideally, you could power it on, see registers, toggle stuff into memory, have lights for interrupts, that kind of thing. Yeah, I know, as soon as I bring up an operating system, the ability to toggle things into memory would be rather dangerous, but I just can't resist the charm of the idea :) So... doable? Impossible? Improbable? John -- Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

16 years, 9 months

1st stage loader for IMSAI - need ascii to binary

by aliensrcooluk＠yahoo.co.uk

YouTube doesn't stream. It slowly downloads the flash video files to the temporary internet files folder where it's usually named "FlaXX.tmp". The XX is usually a hex number depending on how many tmp files you have in there. The file is also (99% of the time) deleted the second you close the page it is linked to. The good thing is that you can watch the video before it's fully downloaded. A very good thing if you are on dial-up :) Does anyone have a list of retro video's on YouTube? I know most can be found by searching for the appropriate machine name, but not everyone has decent tags with there videos :( Regards, Andrew B aliensrcooluk at yahoo.co.uk woodelf <bfranchuk at jetnet.ab.ca> wrote: Right now I am trying to VIEW the %$@! You-Tube stuff. I hate streaming stuf on dial up. I don't think I will ever get more than the 1st few minutes of the UNIVAC stuff. Nothing like comparing almost 60 years of computing development. > Cheers, > Chuck >

16 years, 9 months

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test-drb February 2008