test-drb January 2002

test-drb@ccmp.vtda.org

303 participants
1201 discussions

by pete＠dunnington.u-net.com

On Jan 12, 20:14, jpero(a)sympatico.ca wrote: > Sounds like PSU is reacting to overloading or medium shorts > downstream of that PSU outputs. Also can happen with dried > up capacitors (too high ESR). I don't think it's any of those. The regulators all make a similar noise when I put them on a dummy load drawing 5A, on the bench. And I'm sure it's not bad caps, as two of them are ones I repaired recently. Maybe I'm just sensitive to that frequency range :-( -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

H744 regulator whistle

by pete＠dunnington.u-net.com

I have two H744 regulators in my PDP-11/40, along with an H7441, H745, and H754. I also have two spare H744s and one each H745 and H754. All the H744s emit a fairly loud whistle, and it's driving me nuts. I've seen a note somewhere that a loud whistle is caused by the coil de-laminating, but I don't think that's the case. I tried swapping the two original H744s for spares, no difference. I also tried swapping the coil from the spare H745, which runs almost silently, and that made no difference either. I don't think I can just remove (short out) the coil either, as this is a switching regulator and the coil is needed to make it work properly. Any suggestions? -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

Does anyone have details about the STC ZEBRA? Tony?

by dpeschel＠eskimo.com

STC = Stantec = Standard Telephone and Cable. They sold a truly strange computer called the ZEBRA. It was designed to be cheap (it used a drum for storage and did arithmetic serially). The instruction format is unusual -- 15 function bits (I think each affects a gate) and a 12-bit address of a drum location and a 5-bit address of a "fast store" location (basically a small number of registers). The amount of logic in the machine is small, so the instruction decoding is simple in a sense. But the logic is connected in very subtle ways -- two things can happen independently, or an instruction can set a whole sequence of events in motion. There is an emulator for this machine; I have some of the literature about it too. But I don't have the manual or the schematics, and the literature I have just doesn't make the design "click" into place in my head. The emulator code is not very intuitive either. So that's why I'm hoping someone else has heard of this machine. -- Derek P.S. Tony, I think you would enjoy this design (if you don't already know about it).

22 years, 6 months

KA655 boot PROM errors

by Antonio.Carlini＠riverstonenet.com

> jkunz(a)unixag-kl.fh-kl.de wrote: >t 9e lists this codes as: >42 20051269 Check_for_intrs *** >C6 2004D2F0 SSC_powerup ********* >53 2004E8C0 TOY clock repeat_test_250ms_ea Tolerance *** > >TOY clock is OK, as I expect the NiCd akku to be ded. But >"Check_for_intrs" and "SSC_powerup" are not that explanative to me. SSC is the System Support Chip and it sounds as though the diags are finding something wrong with it. I have no docs that detail much about the SSC and nothing that details exactly what the diags are doing. It does sound as though the chip has some sort of serious failure. I *thought* that the SSC provided the console support too - if that's right then it's clearly not completely dead. Did these errors only start when you swapped cards around? Do thigns work when you put things back as they were? Antonio

22 years, 6 months

H744 regulator whistle

by pete＠dunnington.u-net.com

On Jan 13, 2:54, Sipke de Wal wrote: > Sometimes it helps to fasten coils a bit with siliconekit > or araldite, or if a bit of heat is not a problem thermal-glue > Silicone kit has the added benefit of dampening high freq. > vibrations cause it has a somewhat rubbery constitution.... The coils in H7xx regulators are already encapsulated. Sorry, I should have mentioned that. -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

KA655 boot PROM errors

by jkunz＠unixag-kl.fh-kl.de

Hi. Every time I switch my MicroVAX 3900 on it says: ----- ?42 2 0C FF 00 0000 P1=2004CBA6 P2=FFFFFF0C P3=00000001 P4=00000000 P5=00000000 P6=00000000 P7=00000000 P8=00000000 P9=00000000 P10=00000000 r0=0000000C r1=00000000 r2=00000042 r3=2014078C r4=20051269 r5=20051096 r6=200550A7 r7=00000000 r8=00000000 ERF=80000000 ?C6 2 01 FF 00 0001 P1=00000000 P2=00000000 P3=00000000 P4=00000000 P5=00000000 P6=00000000 P7=00000000 P8=00000000 P9=00000000 P10=00000000 r0=00000000 r1=00000022 r2=00000080 r3=201407A4 r4=2004D2F0 r5=2004D310 r6=2004D316 r7=00000000 r8=00000000 ERF=80000000 KA655-A V5.3, VMB 2.7 Performing normal system tests. 40..39..38..37..36..35..34..33..32..31.. ?53 2 05 FF 00 0002 P1=00000002 P2=00000028 P3=00000000 P4=00D45577 P5=00000000 P6=FFFFFFFF P7=00000000 P8=00000000 P9=20051BD2 P10=20051CE0 r0=00000001 r1=00000001 r2=00000053 r3=00000000 r4=00000002 r5=2004E8F9 r6=200551A9 r7=00000000 r8=00000000 ERF=82000180 30..29..28..27..26..25.. 24..23..22..21..20..19..18..17..16..15..14..13..12..11..10..09.. 08..07..06..05..04..03.. Normal operation not possible. >>> ----- What does it want to tell me? I get the same if I restart it via the reset button after power up. If it was running for a wile I don't get an error on reset. If I switch the power off for a few secounds I get the error again. NiCd akku? -- tschuess, Jochen Homepage: http://www.unixag-kl.fh-kl.de/~jkunz

22 years, 6 months

3com 3station

by jeff.kaneko＠juno.com

On Fri, 11 Jan 2002 10:21:25 -0500 (EST) Pat Finnegan <pat(a)purdueriots.com> writes: > By looking at mine, I can tell it uses a VGA monitor, and has 1M of > RAM (upgradable to 5M with SIMMs I have laying around here). Oh yeah, > it looks to be a 20MHz 80286 also. Yeah, that's the later version. I seem to recall that they didn't make too many of those. . . . > > I still have a copy of 3+Share (and 3+Start) around here > > someplace . . . > > That would be nice if you could find it. However, I won't hold my > breath for it. After attempting to hook an old floppy drive up to it's > 34pin connector, I realized it was definately designed for something else > (one orientation froze the box, the other shorted out the power supply > :-( ) Yow! DOes the thing still light up? I never did fighre out what that connector was for. > I'll take that into consideration. Thanks for the help! Sure. Mebbe I'll have to dredge up my copy of 3+Share . . . Jeff ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/.

22 years, 6 months

OT: DELL SUCKS! Re: PC Gamer, best 50 classic games issue?

by mythtech＠Mac.com

>But if you pick the cheapest, you may find they underestimated >what it took to run a profitable company that will survive, and >6 months later are out of business. > >I've seen it. People that bought from cheap local vendors that >offered 5 year, even lifetime, warranties, gone, gone, gone. > >They come and go like sand on the beach. > >If they want a cheap PC, they have probably doomed themselves >to failure from the outset. I agree, but still, my attitude has become (due to years of dealing with windows and the declining quality of PC hardware), that you can spend $3000 on a PC, or you can spend $300 on a PC, and they are both going to work (quality/stability wise) about the same. Either way, you will wind up with problems keeping windows running. Granted 99% of this is due to windows sucking so bad (if you aren't planning on running windows, then this is a totally different situation, but I am only dealing with advise I give to prospective Wintel buyers). As for if a company will be here in 5 years to support the PC, there are no bets that ANY computer company that is here today will still be here 5 years from now. (perfect example of this. A few years ago, my fire department decided to switch from a Mac to a PC since we need to upgrade the computer anyway. The PC people argued that Apple wouldn't be here in 5 years, so don't get a Mac. Us Mac people pointed out that it doesn't matter, because in 5 years the computer will be ready to upgrade anyway. Well, the vote went to get a PC... and to buy a Packard Bell. Well... Apple is still selling Macs... and Packard Bell... well... they are the ones that are gone... so the computer was replaced AGAIN, this time with a Gateway... who now looks to be dying) But I would still support people going to a fly by night, and risk them going under. I don't advise getting long term support contracts anymore, simply because I am so unimpressed with the support you can get. Phone support tends to be luck of the draw. 90% of the time you get a brainless bonehead. On site tends to be just as bad (I might be in one of those "bad contract support" areas for the local "on site" support options... don't know). So why pay 5 times the price to get a "brand name", when it is going to give you the same headaches as the cheaper CompUSA sold, or mom & pop sold PC. At least if you buy from a local vendor (CompUSA, or a mom&pop), you can carry the computer in to them and bitch to a person... you aren't stuck with phone support. And buy going with a cheap mom&pop... you are more likely to get them to fix it. CompUSA will tell you to contact the computer maker. Although, I do hear good things about the local Gateway Country store in doing on the fly repairs on a carry in. But honestly, I just don't recommend Wintel machines AT ALL anymore. I really tell people to look around and find another option. If you want if for games get a console system, if you want it for internet access, get a used PC (I recommend used Win systems over used Macs for an internet only machine, simply because, like it or not, many web sites cater to windows and IE... that and many of the people that ask me about an internet only machine want AOL, and the windows AOL client is much better than the Mac one), and if you want it for general computing, get a Macintosh. Windows blows, and is no longer worth the money and heartache for new machines unless you NEED it for some reason. But that is just my opinion. -chris <http://www.mythtech.net>

22 years, 6 months

Stan Veit's History of the PC Books - Blow Out - $4 Shipped!

by MTPro＠aol.com

I have a number of brand new copies I'd like to move out. This is a super deal just for classiccmp subscribers. Please e-mail me! For more info on the book, see: http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1289515294 Best, David David Greelish Classic Computing www.classiccomputing.com "classiccomputing" on eBay

22 years, 6 months

Free: 3B2 OS tapes

by mrbill＠mrbill.net

I've got two QIC tapes here: - AT&T 3B2 Operating System Utilities Release 3.2.1 V3 120Mb Tape - Operating System Utilities Rel 3.2.1 V3 Issue 2 (1Q93) Free for the cost of postage. Surely someone has a 3b2 and needs an OS.. Bill -- Bill Bradford mrbill(a)mrbill.net Austin, TX

22 years, 6 months

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test-drb January 2002