test-drb July 2019

test-drb@ccmp.vtda.org

138 participants
116 discussions

by cctalk＠snarc.net

VCF West is this weekend at the Computer History Museum in Mountain View, California. All of the details (and online ticket sales) are at http://vcfed.org/vcfwest. -Evan K.

4 years, 8 months

Resurrecting integrated circuits by cooking them.

by technoid6502＠gmail.com

Yesterday evening, in the process of refurbishing five very badly treated Atari 800 computers I had a hunch and subjected a failed Pokey chip (Atari Part CO12294 Wikki link https://en.wikipedia.org/wiki/POKEY ) to high heat by way of the barrel of my soldering iron until saliva evaporated from it in about 1 second. The chip, which did not work before in any of the machines now works perfectly. Pokey (see wikki link) is common to all Atari 8-bit computers and common in many Atari coinop video game systems. These chips are becoming scarce, so much so there is a sort of replacement being manufactured https://hotrodarcade.com/products/pokeyone-atari-pokey-chip-replacement-for… . The replacement Pokey only emulates the audio portion of the original chip, leaving the PotKEY part unimplemented. Pokey gets its name from Potentiometer Keyboard. It also handles the Atari SIO peripheral signals, so without those an Atari computer cannot use standard peripherals like serial disk drives, and other common interfaces. Thus, for Atari computers a true Pokey is a must. I stumbled upon a fix for this one and wonder if I reinvented the wheel or if this information may be of use to the group in treating other sorts of chips. Reflowing is a treatment for a lot of hardware these days and generally regarded as a hack which won't last. As modern hardware, CPU's and video chips in particular run very hot, I can see how this might be, but Pokey and most of the stuff we work with don't have this environmental restriction. Most of our gear runs at 40 degrees centigrade or lower. So I'm guessing the problem with my disused chip was oxidation within the package and that cooking the chip a bit cleaned things up? Any advise or observations would be appreciated. I tried this on another chip the same evening, an Antic. The Antic DID work for a second or two, whereas it had before given no signs of life, but then returned to its failed state. Best, Jeff (Technoid Mutant)

4 years, 8 months

Searching digital copy of KD11-K (PDP-11/60) Processor Technical Manual

by henk.gooijen＠hotmail.com

Hi Guys, I am trying to get my PDP-11/60 up and running, and I very much like to read the Processor Technical Manual. It?s ?name? is EK-KD11K-TM and I am looking for a PDF of it. I do have this manual on a microfiche, but reading a manual >from the fiche reader screen is not much fun. Maybe I need to find a municipal service that allows you to copy fiche images one by one on A4 paper. The city of Venlo had that in the 1990ies, and I used it to copy the cache manual of the 11/34 from fiche to paper back then. Thanks, Henk

4 years, 8 months

IBM PC-RT 6150 looking for help

by peter＠turczak.de

In preparation of moving, I dug out a IBM 6150 PC-RT from my basement. This was my first proper computer as a child, which was donated to me by a local company that upgraded their CAD system. So it would be interesting to bring it back to life. The machine is equipped with an 320 MB ESDI, 10 MBit Baseband Ethernet adapter and an IBM Megapel graphics adapter. This baby was quite a sight in 1993 when I got it, with its elegant console font designed by Knuth. Now I'm trying to revive the old machine, but there are some hassles: The hard disk seems to be stuck or the drives electronics are broken, it does not spin up. As these drives are quite rare, I'm looking for the SCSI card (Model 6lX700l). Is it right, the PC-RT can boot off SCSI? While I made images of the install floppies, it seems the AIX base system 2.0.0. disk #1 is missing. The AIXWindows floppies where not imaged and seem to be unreadable. Otherwise all VRM/extendes svcs, etc floppy images are at hand. So there is a big pile of problems with this box, maybe someone can help me out with parts and floppy images? Any help would be greatly appreciated. Peter

4 years, 8 months

Intergraph 751 system free to good home, but act quickly

by echristopherson＠gmail.com

There's an Intergraph 751 system (VAX architecture apparently, including hard disk, printer, and two rebadged DEC racks full of who knows what) free to a good home in southern Wisconsin. Appears to be in not-great shape. Unfortunately, it's been on Craigslist for a while and it sounds like the owner's really fed up with it and wants it gone ASAP or a realty company will take possession of it (and who knows what they'll do with it). He originally said last Saturday, but in an email to me yesterday afternoon he said it would have to be gone by today (7/29). Also unfortunately, there have been several people besides myself emailing the owner trying to arrange a pickup, and he hasn't responded to them. I personally have no way to move or store it, so I've been trying to relay what I hear from him to the one person I thought was in the best position to take it. The owner gave me his personal email address and phone number, and told me the name of the realty company in case anyone wants to get it after it's out of his hands; but I don't think it would be cool to post those details here. So please let me know personally if you'd like those details. https://janesville.craigslist.org/sys/d/evansville-intergraph-751/693621784… -- Eric Christopherson

4 years, 8 months

IBM 5160 with oddball MDA input/output card

by jules.richardson99＠gmail.com

Hi all, Someone on one of the Facebook vintage groups found an IBM 5160 with an MDA display for sale in Australia, except that it's a bit odd in that the machine had what appears to be an MDA card, the output of which is then connected via a short external cable to the input on another card, and then an output that card is what's actually hooked up to the monitor. The only internal photo of the machine is very poor, unfortunately. I'm reasonably confident that the "first" card in the "mystery" chain is MDA, it's full-length and alongside the DE-shell video output has the usual DB-25 for parallel. The "mystery" card is also full-length, and there's another full-length card immediately adjacent to it with no external connectors - that one could easily be RAM, or the hard disk controller etc. but I suppose it's possible that the mystery item is actually a two-card set. Anyway, any guesses as to what it might be? The implication is that the mystery card adds functionality to the MDA card (reminiscent of 3DFX boards years later), but of course is operating within the confines of what the MDA display's capable of. cheers Jules

4 years, 9 months

keycaps / switches for Tek 4006

by fritzm＠fritzm.org

Hi folks, I recently obtained a Tek 4006 from eBay as a repair/restoration project. It is missing a few keycaps (both SHIFT keycaps, COPY, LINE FEED, and :/*). In addition, one of the key mechanisms has a broken plunger. Last, the little green paddle line power toggle power switch at the back appears to be broken. Pinging here to see if anybody has spares of these in their collection which they'd be willing to part with? Alternatively, recommendations on compatible key mechanisms/caps, or even 3D models to print some temporary replacements would be appreciated! cheers, --FritzM.

4 years, 9 months

Resurrecting integrated circuits by cooking them.

by technoid6502＠gmail.com

Does this mean that, like me scratching a bit at the package to expose enough nub of broken-off pin to get a blob of solder on to hold a new leg made of wire can theoretically be extended to shaving off the top of the package to expose the IC and then tack soldering the severed wire back onto it? This would probably require some serious equipment I don't have, but sounds possible in extremity. RSVP YHOSvt. ** TNM ** Dwight said: "Message: 6 Date: Thu, 25 Jul 2019 05:52:31 +0000 From: dwight <dkelvey at hotmail.com> To: Pete Rittwage <peter at rittwage.com>, "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: Resurrecting integrated circuits by cooking them. Message-ID: < BYAPR01MB5608F4C8A3860C2A7D2BC172A3C10 at BYAPR01MB5608.prod.exchangelabs.com > Content-Type: text/plain; charset="us-ascii" "Failure of the POKEY chip were likely bonding wire failures. Voltage stress failures are not likely to self repair. I would agree, the fix is likely temporary. Many early chips used gold wire for bonding but later chips used aluminum. Which is better is always a question. The pads on the die were usually aluminum, while the package was often gold. These are acoustically bonded. One wonders if one put a capacitor on the lead with a non-lethal voltage and used such a heating method, it might be able to arc weld the wire back on. Using the method of heating might enhance the success as well. Dwight"

4 years, 9 months

MicroPDP-11/23+ cabinet kit cables

by jnc＠mercury.lcs.mit.edu

> From: Douglas Taylor > I'm putting together a MicroPDP-11/23 in a BA23 box. Have the M8189 CPU > quad width board and the bulkhead cabinet kit .. how the cabling goes > from the M8189 CPU board to the bulkhead cabinet kit? I _think_ this might be the cable you need: https://www.ebay.com/itm/CK-KDF11-CABLE-ONLY-P-N-70-20451-1C/151622708242 but I'm not familiar with the cab kit, so I'm not sure. > The 10 pin connectors on the CPU board don't seem to be keyed ... > Is there something that gives the orientation away? These 10 pin EIA connectors (same in the DLV11-J, KDJ11-B, etc) are keyed, with a missing pin. DEC cables for these connectors have a plug in the matching hole. > From: Glen Slick > In the photos that I have found of the M8189 console panel there is a > '1' just above the top right of the 20-pin connector indicating Pin 1. > A trace can be seen leading from that pin to the baud rate circuitry. > So that pin would go to Pin 1 of one of the 10-pin connectors on the M8189. Y'all love to re-invent the wheel, I see: http://gunkies.org/wiki/DEC_asynchronous_serial_line_pinout#10_pin_header I should check to see if the KDJ11-B has the same external baud rate selection support, and if so, update the page to add it. Oh, that's the other way to tell the orientation, with non-flat-cable cables; with the loopback jumper on pins 7&9. Noel

4 years, 9 months

DEC Pro380 problems

by dittman＠dittman.net

I pulled my Pro380 out of storage after getting a replacement VR201 monitor. I connected it all together and on powerup I get the following display: http://www.dittman.net/pro380/screen.jpg The tech manual says this is an error from slot 1 (the hard drive controller) and the error is "Non-existent memory trap occurred for longer than 20 seconds". I reseated all the cards. I noticed three ICs are missing on the hard drive controller but I don't know if they are empty or someone removed the ICs (I can't remember where I got this system). I can't find a picture of the controller to compare. The missing ICs can be seen here: http://www.dittman.net/pro380/missingics.jpg These are the installed option cards: http://www.dittman.net/pro380/cards.jpg Any ideas? -- Eric Dittman

4 years, 9 months

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test-drb July 2019