test-drb March 2008

test-drb@ccmp.vtda.org

209 participants
369 discussions

by jefferwin＠gmail.com

> > Message: 1 > Date: Sat, 01 Mar 2008 00:31:26 -0800 > From: "Chuck Guzis" <cclist at sydex.com> > Subject: Re: Source for TTL chips > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: <47C8A3DE.23896.8B3FACB at cclist.sydex.com> > Content-Type: text/plain; charset=US-ASCII > > On 1 Mar 2008 at 1:35, Michael Lee wrote: > > > For small amounts I use Jameco Electronics... > > Where does one go to find the not-very-common TTL? e.g., the 7497 > rate multiplier; the 74199 8-bit register, etc. TI had some pretty > estoteric circuits also--74LS362, 74LS444, 74S485, 74S481... > > Cheers, > Chuck > > > I have the same issue. I need three obsolete chips from National Semi, DM 8131, DM 8836 and DM 8837. I have scoured the internet with no luck. I do have a board with these chips in it, I may have to resort to desoldering them. I just hate doing that, it tends to ruin the source board.

16 years, 10 months

board scan, design reconstruction (was IMSAI)

by lynchaj＠sbcglobal.net

> -----Original Message----- > From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] > On Behalf Of Randy Dawson > Sent: Wednesday, February 27, 2008 2:20 PM > To: General Discussion: On-Topic Posts Only > Subject: board scan, design reconstruction (was IMSAI) > > > > > > Date: Wed, 27 Feb 2008 09:48:10 -0900 > > From: grant at stockly.com > > To: cctech at classiccmp.org > > Subject: Re: TTL CPU Re: IMSAI style C&K 7101 switches > > > > At 06:40 AM 2/26/2008, you wrote: > > >Grant, > > > > > > > On a side note, who here would be interested in ultra high [snip] > > > > Hi, > Ive been following this, and maybe I can help. Im a professional PCB > layout guy in my day job. With a schematic and a reasonable resolution > jpeg of both sides (I doubt there was mych multylayer back then) I could > reconstruct the design fairly quickly. Nobody is really going to want to > go down the road of taking a picture and turning it into a gerber, it just > wont work. Id just input the schematic, duplicate the ref des for all > parts, to get the netlist, eyeball the jpeg for placement and throw it at > the autorouter. > > Whats on your top 10 list? > > (S-100) > > CPU card > Dazzler > Byte Blaster > Async card > disk controller card > > I could knock those out in a week or two. > > Randy > > _________________________________________________________________ > Helping your favorite cause is as easy as instant messaging.?You IM, we > give. > http://im.live.com/Messenger/IM/Home/?source=text_hotmail_join [AJL>] Hi, All those S-100 boards definitely sound interesting but here is a twist for something I think would be highly useful for recovering data from vintage computers using generic PCs. How about a PCI floppy controller board? Maybe with some supplementary logic to allow raw track reads? Possibly a BIOS to boot from? An external floppy drive connector? Just wondering how complicated such a thing would be. Thanks! Andrew Lynch

16 years, 10 months

front panel display for a modern PC

by lynchaj＠yahoo.com

I'm curious why anyone would want a front panel with lights and switches. Except for some early IBM mainframe stuff, the number of systems that I've worked with that had no front panel vastly outnumber the ones that did. Indeed, the front panel on the MITS 8800 seemed to be a waste of good components and an anachronism at that. Better to take the costs of the panel and roll them into a good diagnostic ROM with loader. The S-100 followup machine that I used, an Integrand box, had only a reset button on the front panel. I never missed the switches. After the MITS box, I never owned another system with a blinkenlights-and- switches front panel. Just trying to understand. Cheers, Chuck -----REPLY----- Hi, I must have missed the whole "front panel on a microcomputer" thing too. I recall seeing microcomputers with front panels around but never owned one. It has always seemed to me a good boot ROM with monitor is the way to go. Vector Graphic did a good job with their Executive Monitor boot ROMs. I'd rather use a bus probe, logic probe, or VOM when I debug so it can be removed when the machine is finally working. That being said, I still think an IMSAI is a cool microcomputer and would love to get one some day. Thanks! Andrew Lynch

16 years, 10 months

VAXstation/MicroVAX 2000 CPU/FPU overheating?

by ajp166＠bellatlantic.net

> >Subject: Re: VAXstation/MicroVAX 2000 CPU/FPU overheating? > From: Patrick Finnegan <pat at computer-refuge.org> > Date: Sat, 01 Mar 2008 22:02:35 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Saturday 01 March 2008 21:11, Dave Dunfield wrote: >> The extended system tests 101, 102 and 80000106 will not test the FPU >> - this may be normal, I don't know. The docs say they will test all >> hardware which is installed - this may mean that the FPU is not being >> full detected... I don't know. > >Is the FPU socketed? If so, can you remove it, and what the boot and >test output looks like? It's soldered down and not removeable with out the right tools for handling high lead count surface mount. Me I'd pull a old MVII cpu card and do the remove and replace of the FPU and CPU. MicroVAXIIs with good cpus and FPU and bad Qbus interfaces are not uncommon. Allison >I've not had my uV2000 opened up (or even turned on yet...), but that'd >be my next step. > >If you can't remove the FPU (likely), the diagnostics would probably be >complaining about it not working... > >Maybe if I have some time, I'll dig mine out and try playing with it. > >Pat >-- >Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ >The Computer Refuge --- http://computer-refuge.org

16 years, 10 months

Selectric trouble

by dj.taylor4＠verizon.net

At 09:46 PM 3/1/2008, you wrote: >I have a Selectic II that I use now and then. Similar problem. I packed a >few paper towels in there and sprayed a fair amount of good (not WD40) >lubricant (LPS brand if I recall), let it soak for an hour and than wiped >the insides out and removed the towels. It works great. > >This is not a restoration or preservation, but rather how I got a junk >selectric II that I got for free to work wonderfully. Got a new ribbon at >office depot too. If there was one thing I would like to do would be to >have the platen turned down to level out all the pocks from years of use. Do you remember what LPS lubricant you used? I have a 'Ham Fest' IBM Selectric and it sticks a little.

16 years, 10 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, 10 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, 10 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, 10 months

JDR ? Re: Source for TTL chips

by FJGJR1＠aol.com

Hi! I am jumping into this thread late, but has anyone checked JDR in CA? I see that they still have many of these 74xxx series chips. I am interested to tell people about them that buy the 6 Kaypro "8" 's [upgraded / modified Kaypro 4's 1983's] I will be selling on eBay in May / June. Prices are cheap - $0.25 up to a few dollars for Z80's etc. I even became a "commercial customer" with associated small discounts in the 1900's - not good for the bank account howerver!. Many of the others suppliers have gone out of business naturally from that era. I was pleasantly surprised they still supply these so inexpensively.. Just a thought in case it is useful and some did not know about JDR. Frank In a message dated 3/1/2008 8:33:00 P.M. Eastern Standard Time, rtellason at verizon.net writes: On Friday 29 February 2008 16:37, Grant Stockly wrote: > DigiKey or Unicorn Electronics. > > Both want $25 on the order or a handling fee applies. > > Grant > > At 09:03 AM 2/29/2008, you wrote: > >It used to be you could go to Radio Shack and pick up a couple of 74ls02 > >chips as needed. Now it seems there isn?t a source for someone who wants > > to purchase a handful of 74xx ttl chips. I must've missed this the first time around, or it's lower down in the stack... > > I have a ?brand new? s100 SIO card that is just missing the 14 logic chips > > to go in the sockets, but I am not finding a convenient source for them. > > > >Anyone know where I can go to find them in very small quantities? Have a look here: http://mysite.verizon.net/rtellason/w4s.html and use your browser's search function (usually ctrl-F) to find "TTL". That's only the stuff I have a lot of, I have somewhat lesser quantities of other numbers too. -- 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 **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-du… 2050827?NCID=aolcmp00300000002598)

16 years, 10 months

Selectric trouble

by Watzman＠neo.rr.com

Re: On 3/1/08, Robert Ollerton <rollerton at gmail.com> wrote: > I have a Selectic II that I use now and then. Similar problem. I packed > a few paper towels in there and sprayed a fair amount of good (not WD40) > lubricant (LPS brand if I recall), let it soak for an hour and than wiped > the insides out and removed the towels. It works great. > When you did this, did you remove the platen? The upper shell? The lower shell?" **** It is VERY easy to remove the platen, and to remove the entire mechanism >from both the upper and lower case. It can be done in about 20 seconds.

16 years, 10 months

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test-drb March 2008