test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

> From: Johnny Billquist > DEC's memory boards never had any jumpers for PMI as such. Yes, and if you plug one of their PMI memory boards into a Q/Q backplane, it will emit magic smoke, too! :-) I think that's why this thing has the jumpers - to allow it to be used in a Q/Q backplane. It would, of course, only be normal (slower) QBUS memory, but at least one could use it there. However, I am unable to verify that hypothesis. (See below.) I looked at the jumpers along the edge in the C/D finger region, and a lot of them _do_ connect to pins used in the PMI bus. (Confusingly, a number connect to _other_ pins - I can see I have some detective work in front of me here!) However, that made it likely that the one that had jumpers on all those pins was configured for PMI use, so I rolled the dice, and tried plugging that board into a Q22/CD backplane, along with a KDJ11-B, and after a short bout of 'tired memory' (see my previous post), it did come up as a 4MB PMI memory! (Parity, though, not CRC - which might make sense, I guess - it has 148 memory chips on it, which is a multiple of 37, so 32 + byte parity, plus a spare chip, I would guess?) However, when I plugged the other one in - nada. No response at all; the boot PROM bitched about 'no memory at 0'. So I'm not sure _what_ that configuration is for. So then I took a flier (although the cards use the identical PCB, they do have a few minor differences in chip rev in a couple of the programmable chips), and put the jumper config from the working PMI card onto the other card, and it did 'sort of' come up as a PMI card. The boot PROM was complaining about "Memory CSR Error" (I'll have to investigate that further), _but_ the memory was shown (by the boot PROM 'map' command) as PMI, and my own memory-test program showed it was all working OK. Well, at least we have a jumper config that allows us to use these cards as PMI memory! Noel

10 years, 10 months

Tired memory?

by jnc＠mercury.lcs.mit.edu

So I've seen an odd phenomenon on some older QBUS memory boards I've got in. I can't understand it, and I'm wondering if anyone else has i) seen it, or ii) understand the cause. What happens is that the _first_ time I plug them in, some don't work - some (maybe all, sometimes) locations are mangling the data (I forget whether it's dropped or picked bits). Oh, and we're talking 4164's/41256's (or equivalents) here, for the actual devices. However, if I let them sit for a bit (powered off), and then try again, they work fine! I first experienced this phenomenon on some M8044's, which have on-board electrolytic filter caps, so I was guessing it was caused by some sort of noise caused by the caps not working, and after a little while powered on, the caps reformed, and things started to work. However, I just experienced the same phenomenon on a Clearpoint DCME/Q4E board - which doesn't have any electrolytic caps on it. So that can't be it. Anyone have any clue what's going on? (Oh, and of course, for others - if you buy and old memory board, and it doesn't work... don't immediately put it in the 'bad' pile, wait a bit, and try again. You might be seeing this.) Noel

10 years, 10 months

Help needed please re possible loss of a Burroughs B7800 CPU

by nw＠retroComputingTasmania.com

Hi Evan and others who might have been wondering, I managed to find out what happened to the Burroughs B7800 that was "under the stairs" at Monash university. The good news is that the interesting parts, namely the indicator panels, have been saved by the Monash Museum of Computing History. They also retrieved the VAX 11/780 that was there too, and it is now in storage.

10 years, 10 months

Freight recommendation for a teletype?

by rdawson16＠hotmail.com

Hi John, A testament to the extraordinary community that is classiccmp. I will certainly take you up on it, and get you a check, and/or some of the other great junk lying around here. I'm pretty well equipped with a good electronics lab. Do you need a scope? I have a few Tektronix digital scopes and I cant possibly use them all. 100 MHz .... I'm not sure about the lockdown, I imagine when its undone the bolt is stored in a available hole inside, and possibly is still there. I will see what comes back from craters and freighters and UShip, the thing has to be taken off the pedestal and wrapped/banded onto a pallet. Let me know what you need, and hey, Thanks, Randy > Date: Mon, 17 Aug 2015 21:49:59 -0500 > To: rdawson16 at hotmail.com > From: jfoust at threedee.com > Subject: RE: Freight recommendation for a teletype? > > At 09:29 PM 8/17/2015, you wrote: > >123 N Washington St. Elkhorn WI 53121. > >I asked for a quote from Craters and Freighters, and the UShip site. > > I'm not sure if I can help, but I thought I'd chime in. > > I'm 45 minutes from there, 30 minutes if I'm at my fianc?e's place. > (Jefferson, WI and Janesville, WI, respectively.) > > I do have a friend with a loading dock and pallets and wrap. > > You do need to lock down the upper machinery with the shipping bolt > or it'll destroy itself, depending on the shipping method. > > I have a 33 and a 28, too. > > - John >

10 years, 10 months

Z80 / Z84C Swap (Doh!)

by jnc＠mercury.lcs.mit.edu

> From: drlegendre > Sigh.. and here I sit, yet again, with neither a logic analyzer I've bought Tek 1240's (which are really nice units, although of course without the capabilities of today's - but still a lot more powerful than the earliest LA's) on eBay for as little as $25 (albeit without leads), and I gather there are modern units which plug into a PC with a UCB port for not much more money. Yes, a lot of the older machines were built without benefit of them (pretty much all their builders had was 'scopes), but there are so many things where one cannot easily create a 'scope loop, and for investigating those, a logic analayzer is the perfect tool. It's just a critical tool to have if one is going to _repair_ old computers - only slightly less critical than a VOM. No ifs, ands or buts. Noel

10 years, 10 months

Z80 / Z84C Swap (Doh!)

by drlegendre＠gmail.com

As the proud owner of an NtM Osborne 1 computer, courtesy of our own Jules Richardson (and another list member), I made no delay in opening the case to install a missing CPU. Jules was kind enough to let me know about the missing part prior to handing the old girl over to me. I'm sure you've already figured out what happened - unaware that the Z84C series was CMOS, that's what went into the Osborne's CPU socket. The machine came to life with a garbage display and howling on-board beeper. Tried resetting it a few times, all I got was more and different noise & garbage. That's when I shut down and did some reading - initially, I thought it might be a clock speed issue - sometimes 'faster' chips won't run at slower clock rates. What I did learn is that Z-80 were made in CMOS versions, and the Z84C is one. So what did I most likely do, here? Hose the CPU for sure? Collateral damage on the board? Both / Neither? As ever, it's what you don't get, that gets you.

10 years, 10 months

SCSI Tape to TAP utility

by marc.verdiell＠gmail.com

Thanks Al, I downloaded the assembler just in case. And to Chuck's point, it always felt like the MSDN distribution was a poorly documented, disorganized mess. I was not impressed. The old Turbo C and new Watcom C are available freely for DOS 16 bit and people say very good things of both. Marc > From: Chuck Guzis <cclist at sydex.com> > >> On 08/14/2015 12:00 PM, Al Kossow wrote: >> >> last 16 bit compiler is visual C++ 1.52c >> >> also ran across MASM 8 >> >> https://www.microsoft.com/en-us/download/details.aspx?id=12654 >> >> if you need it > Schizophrenic MS labeling. The C++ suite is 1.52c, but the compiler > identifies itself as 8.00c. Crazy. > > --Chuck

10 years, 10 months

Anyone have a Lockheed SUE?

by COURYHOUSE＠aol.com

think dcc made a fake dg nova also!? In a message dated 8/14/2015 8:24:14 P.M. US Mountain Standard Time, aek at bitsavers.org writes: oops, it's actually a Digital Computer Controls DCC-112

10 years, 10 months

Freight recommendation for a teletype?

by COURYHOUSE＠aol.com

only think that worries me is some guy in the suv takes a liking to it and "opps" he says " someone took it when I was in the restaurant!" Ed# In a message dated 8/17/2015 4:25:49 P.M. US Mountain Standard Time, rdawson16 at hotmail.com writes: Thanks Cory, I listed it with UShip, and will wait to see what happens. This was a great idea, I never heard of such a 'crowd-sourced' shipping service before. Randy > Subject: Re: Freight recommendation for a teletype? > From: coryheisterkamp at gmail.com > Date: Mon, 17 Aug 2015 17:33:38 -0500 > To: cctalk at classiccmp.org > > Randy, > > One option might be UShip. These are best transported laying down once the paper and tape spindles are removed and preferably, that shipping screws anchor down the chassis (though I have moved them without). With UShip, you set an asking price with parameters, such as blanket wrap, or covered shipping. Everyone from professionals to those with room to spare in their SUV can then ask questions, accept the terms, or counter-offer. They don't get paid until you've received the item and are satisfied. With items like this, I almost prefer a private individual rather than a professional (bulk) mover. -C > > > On Aug 17, 2015, at 5:26 PM, Randy Dawson wrote: > > > Hi Classiccmp, > > > > I just purchased a ASR 33 teletype and now stuck with the problem of getting it here, its in Wisconsin and I am in LA. > > > > Its pickup, the owner will not pack and ship. > > > > Do you know of a freight company that will put it on a pallet, band it with care and take care of the shipping? > > > > Randy > =

10 years, 10 months

Speaking of Creating 5 1/4" floppies

by jws＠jwsss.com

I wonder if someone can help with a bit of a problem I have. I have a compaq portable 3 system which has a working Pick (Non dos) system on it. It has the 5 1/4" floppy drives on it. I am looking for a bootable floppy or 2 with something like dos 6.x on it and some utility that can read and write disk sectors. Preferably the latter is a nice gui program, but beggers can't be choosers. I need to boot it up from the floppy drive and modify the pick system dictionary to remove the main password. So the change to the system will be surgical, just one sector. If anyone can help, can you send me a note and let me know how I can compensate you for your help. If I really move crap around I may be able to find a system with the 5 1/4" floppies on it, but I'm not sure I could get a program onto the system then out to the 5 1/4" drive and am also looking for suggestions about what disk utility / editor might be useful if anyone has suggestions on that. I'll go ahead and dredge up something soon if I can't get help from somewhere. thanks Jim Stephens

10 years, 10 months

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test-drb