test-drb January 2008

test-drb@ccmp.vtda.org

221 participants
430 discussions

by cclist＠sydex.com

> Date: Wed, 23 Jan 2008 10:24:27 -0800 > From: Al Kossow <aek at bitsavers.org> > In Aug, 2004, Jim Battle wrote: > > > Speaking of core memory, I used to work for a company that was still > > shipping core-based systems in 1985, when I first joined them right out > > of college. > > The machine was the "BTI 8000", made by BTI Computer > Systems, based in > Sunnyvale, CA. I worked there for only a year, but I > have some > recollection of the machine. > > > I turned up a brochure and technical summary last night, scans up under > http://bitsavers.org/pdf/bti Holy cow--3.5 years to respond to a message! I'm not certain, but I think I may have a boot disk for the 8000, should anyone run into the real thing. Cheers, Chuck

16 years, 5 months

Need 28VDC 4Amp PS...

by cclist＠sydex.com

> Date: Wed, 23 Jan 2008 16:52:23 -0500 > From: "Bill Sudbrink" <wh.sudbrink at verizon.net> Give http://www.jameco.com a shot--they have a bewildering thicket of power supplies in stock. The hardest part is getting through their inventory listing. Cheers, Chuck

16 years, 5 months

Grid MS-DOS 3.3

by cclist＠sydex.com

If anyone else needs MS-DOS 3.3 for the Grid PC, I've put it up at http://www.sydex.com/temp/griddos.zip. Two self-extracting 720K diskette image files and Grid PCMASTER and PCSLAVE data transfer programs. Note that this version of MS-DOS includes enhancements for the Grid PC. I'll leave it up until Friday. Cheers, Chuck

16 years, 5 months

My reply - Re: OLD Computer Magazines to go

by FJGJR1＠aol.com

Dave, Thanks for replying to my other email. I am preparing a detailed reply, but have been busy with some other high priority projects. Overall, you seem to be the best source for and to send to such magazines! I am developing a list of sites related to Kaypros and other older computers I have found and will post it on several websites when I get it done. Those are areas to explore, but you probably know of most of them already. Some of these sites may be good candidates for such magazines. It is a shame all this cannot be saved by someone or some organization, but you just cannot save everything. Once they are gone, you cannot get them back. All the best! Frank **************Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489

16 years, 5 months

Dead IBM PC 5150

by cclist＠sydex.com

On Tuesday 22 January 2008 22:53:42 Chris M wrote: > what examples could you give as a not so conventional > 8088 board? The console control in the Ruffatti pipe organ at St. Mary's Cathedral in San Francisco? (I don't recall exactly--could be an 8086). Cheers, Chuck

16 years, 5 months

Subject: Re: div by 10 on Z80 was RE: Reading Polymorphic

by cclist＠sydex.com

> Date: Mon, 21 Jan 2008 18:30:10 -0800 > From: dwight elvey <dkelvey at hotmail.com> > I think the restore operation will cause a carry meaning I need > to clear it here with something like: > > ora a ; or other carry clearing instruction I don't think so--let's consider a simple case, using 8 bits and -10. -10 = 0xf6 Our code looks like: add -10 to dividend skip next instruction if carryout subtract -10 from divident The question is "what is the value of the carry bit here?" Let's try some sample values. 0 + 0xF6 = 0xF6, no carry, subtract 0xF6 = 0, no carry/borrow 9 + 0xF6 = 0xFF, no carry, subtract 0xF6 = 9, no carry/borrow 10 + 0xF6 = 0x00, carry; skip the subtract 11 + 0xF6 = 0x01, carry; skip the subtract So the "ora a" to clear the carry shouldn't be required. Saves a few more cycles. For those porting this method to other platforms, be aware that the 6502/PIC subtract works differently than the x80; the carry bit represents "not borrow" instead of "borrow". The same algorithm can be implemented nearly as efficiently on the 8085 by using the "undocumented" instructions, as it includes a double-precision subtract (as well as a 16-bit arithmetic right shift) as a 1-byte instruction. Note that the BC pair must be used in place of DE to use this instruction. It might be possible to implement the algorithm efficiently on the 8080 by letting BC = -DE and using an ADD HL,BC instead of a SBC HL,DE. One is left without a loop counter register however--but then one could "prime" the A register with a 1 and iterate until the 1 migrates to the sign bit of A, then mask it out as part of the exit code. Cheers, Chuck

16 years, 5 months

the PAL

by chrism3667＠yahoo.com

16L8ACN. This is the PAL aboard the Acculogic sIDE-1/16 XT-IDE controller I mentioned. Someone asked :) ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

16 years, 5 months

Dead IBM PC 5150 motherboard - help troubleshooting

by daviderhart＠oldzonian.com

> >You should indeed have activity on the address lines, take another look as the >machine comes up, they should be toggling, even briefly. Could be that data >lines are stuck, and/or it is getting a halt somewhere. Another trick would >be connect a 1k to +5, and touch it to the reset line, you should see the >address lines blip a little then. If they never change state the processor is >dead or the mux buffers stuck (74245's?) . > >If you can build a little proto board to plug into the processor socket so you >can disconnect the address lines from the board, you should be able to 'free >run' the processor, and see activity. If those address lines dont toggle with >clock, power applied and reset low, I would suspect the processor. > >Randy > > >> Date: Tue, 22 Jan 2008 19:26:49 -0800 >> From: jwstephens at msm.umr.edu >> To: >> Subject: Re: Dead IBM PC 5150 motherboard - help troubleshooting >> >> Richard Beaudry wrote: >> > <snip> >> > 6) One thing that seems odd is that the ADxx (Address/Data) lines seem >> > "stuck". The scope does not show a waveform, and measuring with a meter >> > shows some lines right at +5VDC, some at about +4VDC and some at 0VDC. >> > Perhaps the processor is indeed HALTed??? >> > >> On several of the CPU's if you hold the processor reset, you actually >> get the reset vector address out. So on the 8088 8086 80186, you get >> FFF0 out. I don't know if 8088 has all 16 lines out, or is multiplexed, >> but on the 186 we could troubleshoot a board we had with a 186 on it for >> a support processor by setting a flipflop that held it reset, and then >> look at the lines with a scope. >> >> Jim > I did some troubleshooting of some of my 5150's using the "Sam's IBM PC Troubleshooting and Repair Guide Book". I noticed that there is one on eBay right now, item #190193033366. Might help. david.

16 years, 5 months

youtube movie of making a vacuum triode.

by dkelvey＠hotmail.com

> From: rtellason at verizon.net > > On Wednesday 16 January 2008 08:21, Gordon JC Pearce wrote: >> On Friday 11 January 2008 15:36:05 dwight elvey wrote: >>> Although, a side subject, I like Jay, consider tube manufacture >>> relavent to some of my computing equipment. >>> Dwight >> >> I wonder how much computing equipment you could make from home-made >> triodes? >> >> Even a simple (say 4-bit) adder would be pretty impressive. > > In power as well. > > It'd be darn-near EMP-proof, though. :-) > Hi I thought I might clarify what equipment I had. First it is not digital, it is an analog computer. Each tube calculates to about two decimal digits making each tube worth about 20 or so TTL equivalent. Dwight _________________________________________________________________ Climb to the top of the charts!? Play the word scramble challenge with star power. http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_jan

16 years, 5 months

HP/CHM software release update?

by Tim＠Rikers.org

I email Al, but did not yet get a reply. I realize folks are busy, so I thought I'd ask on the list for an update. Anyone know the status on releasing the older Hewlett Packard software that the agreement with the Computer History Museum allowed for? I know there are others on this list that have HP software, is it now legal to put that up someplace? or does it need a CHM stamp of some kind first? Is the agreement available for review? Side Note: I'll be in San Jose tomorrow (Jan 23) and plan to drop by the CHM in the afternoon. I'll hit some stores and scrounge sites in the area as well to see what I can find that I can't possibly take back on the plane with me. :) You suppose I could check an HP-2116 as luggage? 230lbs might be a bit over the weight limit, but it's close, right? :) -- Tim Riker - http://Rikers.org/ - TimR at Debian.org Embedded Linux Technologist - http://eLinux.org/ BZFlag maintainer - http://BZFlag.org/ - for fun!

16 years, 5 months

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test-drb January 2008