test-drb February 2004

test-drb@ccmp.vtda.org

275 participants
504 discussions

by dwight.elvey＠amd.com

Hi This is a good idea. Loads change as things warm up. It seems like I recall that there were some RAMs that needed to be written once before they worked properly. I don't know if these are among those. Still, John's suggestion is where I'd look first then you should type replacing the RAM's with a different manufacture. Dwight PS I currently work at AMD but these RAMs are way before my time here. >From: "John Lawson" <jpl15(a)panix.com> > > > > One thing to test: since you have been experiencing power-supply >gremlins - if you have a scope (or a DVM that measures AC millivolts) >you might want to put it accross the power lines to the card, to see if >there is a high value of 'ripple' riding on the DC lines - Excessive >ripple can cause nasty little transient glitches like you describe. Then >you can look to the filter capacitors to see if they might not need some >TLC as well. > > Just a Thought... > >Cheers > >John > > > >

20 years, 10 months

FidoNet message archives?

by healyzh＠aracnet.com

I was just thinking about how useful the Google archive is, and wondering, has anyone created an archive of the old FidoNet message archives? Unfortunately I assume most were lost due to the cost of archiving them. Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh(a)aracnet.com (primary) | OpenVMS Enthusiast | | | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

20 years, 10 months

Microfiche User's Guide -- DEC PDP

by CyndeM＠vulcan.com

Hi Gang I'm looking for PDF files or other images of various hard copy manuals (4 x 6) that describes the contents, organization, and updating of the various PDP Microfiche Libraries. Also, if there is a document that describes the entirety of the Microfiche libraries, or websites with stories about DEC Microfiche, that would be very helpful. I'm organizing a whole boatload of these Fiche sets right now, and any tidbits of information would be really nice. Thanks! Cynde Moya, MLIS Archives Cataloguer Vulcan Inc. www.vulcan.com cyndem(a)vulcan.com Office Tel. 206-223-4901 Mobile Tel. 206.369.3205 Fax. 206-223-4207

20 years, 10 months

RAMTESTing a Horizon

by RMaxwell＠atlantissi.com

Thanks to all those who provided insight in the "Smoke on the Horizon" thread... You may be happy to hear that the machine is running now: all the blown tantalums are replaced, as well as the regulators that may have suffered due to untimely capacitive departures. I took warnings about the -5V supplies to heart and replaced all the tantala (plural of tantalum?) around the negative supplies, largely because the -5V regulators are powered >from the -16V unregulated line, and the worst failures happened on caps across the +16V line. Now that the smoke has cleared, I've been RAMTESTing the 64K HRAM card, and am a little distressed to note failures. These usually occur when the program is run from fresh-from-startup RAM: once RAMTEST (3 or 5) has run through a cycle (or bombed due to an error), subsequent tests run for hours with no further problems. The failures don't seem to be bit-specific, but they've occurred mostly in the highest 16K (particularly the top 8K) of address space. Do I need to be concerned about this? Anyone know if the RAMTEST program trips up on previously-unaccessed space? Or do the RAMs need a little time/exercise to get to an internal temperature where they are stabler? These are 16Kx1 AMD devices (circa 1982), and my debug work in the past has been limited to SRAMs or higher-density DRAMs (I know, I know: I just haven't lived until I've debugged core). Regards, Bob

20 years, 10 months

Pdp 11/20 front panels

by chad.martin＠fli-invent.com

I own an early 11/20, sn300, also of the PDP-11 only markings, like the unit in question. My front panel PCB is date stamped 1970, and it is the led type. I also have original DEC schematics that show first bulbs, and then a revision to allow bulbs or LEDs. I also have some other front panel PCBs with bulbs. My best guess would be that they did a revision for LED's, and then perhaps dropped them due to cost or availability. So it appears that LEDs were at least installed on some 11/20s. My LED unit does not have the front panel drilled out, but I suppose they may have done that for one of the early proto types while they were trying different designs. My 11/20 was supposed to have been gotten from the dec Mill factory in Mass, perhaps the early LED units were never shipped out. So it is likely that the 11/20 for sale is for real. Chad Martin

20 years, 10 months

PDP-11 on VCM

by wmaddox＠pacbell.net

I would like to make it clear that the seller of the PDP-11 (the 11/20 marked 11) listed on VCM is as far as I know a perfectly honest gentlemen and was not trying to be deceptive about the condition of the machine he is selling. Indeed, the pictures are up in the listing for all to see. I take issue with the description of the front panel as "very nice" if in fact it has been modified by a user, but it is certainly a subjective matter and it appears that the seller was acting in good faith and did not realize that his machine was unusual in this respect. He's apparently been busy with multiple obligations, including arranging the shipment of some other much larger machines, and just hasn't had time to deal with the 11/20. He got back to me in email yesterday, explained the situation, and was distressed at the implication that he had been deceptive. I had him pegged as an Ebay-style "Altairz" mercenary who didn't really know what he was selling but was holding out for a windfall, and I my tone reflected that. I believe that was a mistake, and that he is a serious collector as he claimed to be in his mail. A bit of Googling turned up several archival messages that indicated prior participation in the classic computing community. In the interests of full disclosure, I should also say that I haven't entirely lost interest in the machine myself, and anyone who is interested should look for themselves and draw their own conclusions about its value. Bill Maddox

20 years, 10 months

Archive 5945C

by aek＠spies.com

The 5945C has an edge connector , much like a print card. Dont know how to put it more precisely -- A 5945C is the basic QIC-36 interface, 5945L is QIC-02 www.bitsavers.org/pdf/archive/ScorpionProdDescr.pdf

20 years, 10 months

Everex EV-831

by TRASH3＠splab.cas.neu.edu

I just sent email to the 4 persons asking about the files I had. If you didn't get the email, let me know. joe heck

20 years, 10 months

afrts 33 RPM records from the 70s - what do I do with them?

by tosteve＠yahoo.com

I have a 2-foot stack of old afrts (Armed Forces Radio and Television Service) LP records from the 70's. They are used, but in good condition. They have the offficial afrts label with records contents listed. What should I do with them? (be nice) Examples: Kris Kristofferson David Cassidy Barbara Streisand Roy Clark Sweet DeFranco Family Dawn, featuring Tony Orlando John Lenon, Yoko Ono Michael Jackson Rick Springfield __________________________________ Do you Yahoo!? Get better spam protection with Yahoo! Mail. http://antispam.yahoo.com/tools

20 years, 10 months

HP 2100/21MX assembler question

by jwest＠classiccmp.org

If one codes a set of "micro" instructions in the Alter-Skip-Group as follows: LBL1 CLE,SEZ CLear E, Skip if E Zero Instruction 002140, would not one expect this to always skip the next instruction??? I would think E has been cleared, so the Skip if E Zero becomes true. Jay West --- [This E-mail scanned for viruses by Declude Virus]

20 years, 10 months

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test-drb February 2004