test-drb August 2001

test-drb@ccmp.vtda.org

295 participants
726 discussions

by pete＠dunnington.u-net.com

On Aug 21, 22:18, Adrian Vickers wrote: > At 01:06 pm 21/08/2001 -0600, you wrote: > >If the CPU's broken, surely you can get that ... > > I expect Farnell carry it (that's where I got the Z80 prices from), but a > quick search on "6502" revealed nothing; but I only did it quickly, so may > have made a mistake. I'm fairly sure 6502s are still available from one of the UK suppliers. > >The ROM's are probably pin-compatible with some flavor of EPROM, and > somebody, > >somewhere, surely has the working ROM's ... > Hmm, possibly. Yes to both parts -- on the 8032, the ROMs can be replaced by Texas 2532 EPROMs (that's from memory but I might be able to look it up), and I have dumps of the ROMs from my 8032 (which I sold a while ago). -- Pete Peter Turnbull Network Manager University of York

23 years, 4 months

CBM 8032 SK (& electronics)

by mcguire＠neurotica.com

On August 24, Absurdly Obtuse wrote: > > I dunno about that. In the past 24 hours, I've worked on the > > innards of an SGI Onyx, an AlphaServer 2100A, and a PDP11/34a. I'll > > take the 25-year-old PDP11 over any of them, physical design wise. > > I think he might have been referring to older micros, Dave. Ahh, in that case, I agree. 8-) -Dave -- Dave McGuire Laurel, MD

23 years, 4 months

where to find old ICs ?

by uban＠ubanproductions.com

I am trying to collect a few spares of some old ICs so that I can continue to maintain my older DEC PDP equipment. Last night I diagnosed a bad 74H00 in my PDP 11/45 and when I realized that it was a hard to find component and that it was only going to get more difficult to find, I created a list of parts which I might need and do not have. If anyone has additional information about any of these parts (data sheets for the ROMs, etc.) or information on possible substitutes, it would be appreciated. Also, if you know of a source for these parts, that would be good too. --tnx --tom DM8598-AB ROM DM8598-AC ROM DM8598-AD ROM 3101 256x4 ROM 3101A 256x4 ROM 74187 256x4 ROM 74182-1 look ahead carry generator (fast version ?) 74194 4-bit bidirectional universal shift register 74H01 quad 2-in nand gates w/open collector outputs 74H10 triple 3 input nand gates 74H21 dual 4-in and gates 74H22 dual 4-in nand gates w/open collector outputs 74H30 8-in nand gate 74H40 dual 4-in nand buffers 74H50 dual 2-wide 2-in and-or-invert gates (one gate expandable) 74H74 dual d-type positive edge triggered flip flops w/preset & clear 74S15 triple 3-in and gates w/open collector outputs 74S65 4-2-3-2-in and-or-invert gate w/open collector output 74S74-45 fast version (4.5ns) of 74S74 ? Where these parts made by or for DEC? DEC380 DEC380A DEC8001 DEC8251-1 DEC8815 DEC8815A DEC8875 DEC8881 DEC8885 DEC9318 Also some transistors: DEC4258 transistor DEC30098 transistor

23 years, 4 months

test

by Glenatacme＠aol.com

test

23 years, 4 months

Just out of curiosity..

by technos＠nerdland.org

Just out of curiosity, how often do y'all get 'data retreival' requests, where some schmuck tosses you a tape from 1980 and needs the data? Jim

23 years, 4 months

SemiOT: Mourning for Classic Computing

by mmcfadden＠cmh.edu

Here we go with the language discussion. First I put on the flameproof suit, insert ear plugs, cover eyes with antiflash goggles, and place flack vest on front and back. Are any of the following a computer language? IBM JCL IBM assembler DCL SPSS SAS BMDP C Datatrieve HPGL At some time in my life I have solved problems with all of them. I peek out to see if there is superheated steam in the area and then check Geiger counter for background radiation levels. My only comment is that you should pick the language you like and that can solve your problem. I'm too old to be intolerant. Mike

23 years, 4 months

Switching PS for S-100 Computer?

by r_beaudry＠hotmail.com

>Date: Wed, 22 Aug 2001 19:44:49 -0400 >From: "ajp166" <ajp166(a)bellatlantic.net> >Subject: Re: Switching PS for S-100 Computer? >From: Rich Beaudry <r_beaudry(a)hotmail.com> >>I would like to ask if any of you know of an existing, available, commercial >>switching power supply that could be used to power an S-100 computer? > >WHY???? The bus voltages for S100 are UNREGULATED. OK ... so how does this change things? If I have an unregulated 8 Volt power supply, and the regulators on the cards regulate that down to 5 V, how is that different from having a regulated SMPS at 8 volts, and still having the regulators drop it down to 5 Volts. Perhaps stupid, but is it technically possible, and will it work without harming the boards? I thought it would be easier to get a modern supply, so I wouldn't have to try to build one... Of course, now that I look at the prices for SMPS.... YIKES! >> realize I could get a +5V and +/- 12V supply >> and just remove the regulation circuitry on the cards >Only if its an old LINEAR supply as SMPS designs mostly will not dot it. I'm not sure what you mean by that.... >The S100 power supply is terminally simple. Three transformers >{8,16, 16 V AC}, three bridge rectifiers and three caps... thats all >folks. Yup, I know ... Try finding a new, "available from a distributor" transformer these days that will handle these voltages and currents, and I will quietly slink off... That's the reason I'm looking for alternatives. I can't find a transformer that will give me the voltages and currents I need. Links to these distributors are welcomed... Rich B.

23 years, 4 months

classiccmp Jobs?

by mcguire＠neurotica.com

On August 23, Jeffrey S. Sharp wrote: > It's time for me to look for a job. I've been unemployed (voluntarily, > happily so) for a month, and re-establishment of a dependable cash flow is > becoming a top priority. Since I'll be finishing college next May, it's > also time to begin looking for my first post-college position. > > Can a programmer make a career out of classic computing? I dunno...I pick up VMS consulting work from time to time. Of course, it's been on releases of VMS that are merely a few months old, but to the "outside world" anything that's not Windows is "classic" and "obsolete". So YMMV. -Dave -- Dave McGuire Laurel, MD

23 years, 4 months

Apple II software, system discs, blank disks? Help!!

by CELang＠worldnet.att.net

I phoned my local Radio Shack store. They have 5 1/4" diskettes, double density, three to a package for $1.97. Or I should say they *did* have them. I just cleaned them out. Just amazing the old media Radio Shack has. Diskettes, reel to reel tape, even Beta tapes. If I felt more smart alec I might've asked the clerk if he had any HP 79xx disk cartridges. :) Craig -----Original Message----- From: Sellam Ismail <foo(a)siconic.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Thursday, August 23, 2001 3:52 PM Subject: RE: Apple II software, system discs, blank disks? Help!! >On Thu, 23 Aug 2001, Rich Beaudry wrote: > >> As to a source of 5.25" disks, I hate to mention it, but eBay is >> actually good for this. Bargains can actually be had... > >Try thrift stores! You'll find more than you'll ever know what to do >with, and cheap! Sometimes you can find some new in the box with >shrinkwrap even. > >Sellam Ismail Vintage Computer Festival >--------------------------------------------------------------------------- --- >International Man of Intrigue and Danger http://www.vintage.org > >

23 years, 4 months

2/3 drives (was: TRS80 help needed

by pete＠dunnington.u-net.com

On Aug 23, 10:28, Fred Cisin (XenoSoft) wrote: > Quick simple puzzle: why would a drive that steps both disks at the same > time be significantly SLOWER when DISKCOPY'ing a disk than using separate > drives? > Hint: MUCH faster when copying if you write software specifically for it. Because it will read some number of tracks, stepping inward as it does so, then have to step back to the correct track to start writing. Example: read tracks 0 to 19 (20 in total, 19 steps), step back 19 tracks, write 20 tracks (19 steps again); repeat. Total number of steps to copy n tracks is just less than 3n. If you want to read the tracks back to verify them, life is even worse, as the total is almost 5n. On the other hand, if you do it one track at a time: read a track, write that track, then step forward one track, the total number of steps to copy n tracks is n-1 steps. And still only n-1 if you verify each track as you go. -- Pete Peter Turnbull Network Manager University of York

23 years, 4 months

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test-drb August 2001