test-drb March 2022

test-drb@ccmp.vtda.org

87 participants
62 discussions

ID UV erasable PROMS used on an IBM PC board?

by organlists1＠sonic.net

I cannot find a datasheet by any of the numbers silkscreened on these ICs. Could these be proprietary IBM P/N numbers? https://www.dropbox.com/s/f6rvemx9ldbbv5x/EPROMS1.jpg?dl=0 No need for a Dropbox account, close the login pop up and you can view the image. Thanks Don Resor

2 years

Searching cctalk archives?

by ccth6600＠gmail.com

I came across a reference to a cctalk message from 9 September 2006 and would like to read the rest of the thread with the subject "PDP-8m Console Switch Problems - fixed!". Unfortunately it appears that the cctalk archive does not go back to 2006. Is there some place with the complete cctalk archive or at least back to Sept 2006? I have also been trying to search the cctalk archive, but short of downloading every month and unzip it, there appears to be no easy way of searching. What do experienced cctalk members do? Thanks Tom Hunter

2 years

DEC DC319A DLART (DL11 Compatible Asynchronous Receiver-Transmitter)

by pbirkel＠gmail.com

In case anyone else has been looking some of these, there is a listing for multiple tubes-of-11 on eBay at a moderate price: https://www.ebay.com/itm/123710245814 QTY-11 PCS. AMI SEMICONDUCTOR DC319 C04090 Integrated Circuit - (UIC 40378901) It's documented in the DEC Semiconductor Data Book, Volume 1 (1987), pages 3-27 through 3-41: http://bitsavers.org/pdf/dec/semiconductor/ -----

2 years

Re: Unusual “gold” IC chips?

by bmr＠ringman.ch

Those look like "stripline" RF/microwave packages. PCBs will have cutouts for the package body, so that the leads can be soldered flat (no bends) directly onto impedance-controlled leads on the board. On Tue, Mar 22, 2022 at 6:17 PM Oldcompu via cctech <cctech at classiccmp.org> wrote: > Anybody know what these are? Maybe RF related? Found on a box of computer > ships. > > https://share.icloud.com/photos/0294pRVHPFQMShUZic2vFvneg > > >

2 years

NEW CONTRIBUTION TO US CALL-A-COMPUTEER BIG 3 INCH 3 RING AS NEW TIMESHARE MANUAL

by couryhouse＠aol.com

NEW CONTRIBUTION TO US "CALL-A-COMPUTER"? PILLSBURY? TIMESHARE...? ?WHAT? SYSTEM WAS? THIS? RUN ON ?? ? ?IT IS A? BIG 3 INCH 3 RING AS NEW TIMESHARE MANUAL.? THANKS? ED#? ? SMECC MUSEUM

2 years, 1 month

ID UV erasable PROMS used on an IBM PC board?

by organlists1＠sonic.net

This is the CPU board out of a first generation 1982-83 IBM Electronic 85 Typewriter (Electronics Driven Selectric). I was looking to archive the software/firmware from these. The machine was exposed to some dampness. Corrosion has ensued on the interface connector between the CPU and driver boards. The next year, more energy efficient memory ICs were used. Memory power failure back up only consisted of 3 AA batteries and could last up to one year. The predecessor (this board) required 6 AA size Nicads and would only retain memory for a few hours. IBM using their apparently very large stock of OLD aluminum covered ICs in as many products possible I guess. Don Resor -----Original Message----- From: wrcooke at wrcooke.net <wrcooke at wrcooke.net> Sent: Sunday, March 20, 2022 7:13 PM To: D. Resor <organlists1 at sonic.net> Subject: Re: ID UV erasable PROMS used on an IBM PC board? > On 03/20/2022 8:59 PM D. Resor via cctalk <cctalk at classiccmp.org> wrote: > > > I cannot find a datasheet by any of the numbers silkscreened on these ICs. > > Could these be proprietary IBM P/N numbers? > > https://www.dropbox.com/s/f6rvemx9ldbbv5x/EPROMS1.jpg?dl=0 > > No need for a Dropbox account, close the login pop up and you can view > the image. > > Thanks > > Don Resor More details would help. What is the board? Do you know at what address in the PC memory map they fit? Based on the info you gave and the picture I would bet $1 they are standard 2764 chips. The 2764 was the first standard chip to have 28 pins. The size of the die visible through the quartz window is consistent with 2764 (as opposed to 27128 or 27256) and the fact there is room for 3 which would give 24K total. The PC didn't have a lot of places in the memory map that would allow more than 24K. Three 27128s would be 48K (a LOT in those days) and the 27256 would be 96K. I can't help with the part numbers. But I doubt they are IBM proprietary. The vast majority of chips used in the early PC line were standard from other companies. Will

2 years, 1 month

ID UV erasable PROMS used on an IBM PC board?

by organlists1＠sonic.net

2 years, 1 month

restoring a Silent 700 Model 765

by spectre＠floodgap.com

I found my old Model 745 in storage and other than needing a print head clean and adjusting the printer contrast, it works splendidly. It has the manual and I've got some plugs to build it an RS-232 connector when I find some more round tuits. This whetted my appetite for other 700s, including the (in)famous bubble memory 763/765. I was able to land a set of 765 ASRs. One of them came with Telenet transcripts from The Source (various logins from 1978 to 1980), which was really cool reading. I'll scan these. However, neither of them work. Both power on, but they immediately go into COMMAND mode and sit there, which appears to be abnormal behaviour based on what I'm reading in the service manual (thanks, Bitsavers!). The NUM LOCK switch works and the paper advance works, but nothing else appears to elicit a response. One of them advances the page and acts like it's printing the command prompt, but the other one doesn't even do that. The service manual suggests I need to replace both the TMS 9980 and 8080 boards, which would really suck. I'm hopeful that the one that's "more active" has a working 9980 board and I can use the 8080 board from the other one. (I haven't even gotten to the bubble memory yet.) Anyone repaired these units or have an idea of a repair strategy other than replace damn near everything? TELENET 303 8A TERMINAL= @C 301 24 301 24 CONNECTED DIALCOM NETWORK SYSTEM 10 -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- Simplicity is the ultimate sophistication. -- da Vinci ---------------------

2 years, 1 month

restoring a Silent 700 Model 765

by spectre＠floodgap.com

>> 301 24 CONNECTED >> DIALCOM NETWORK SYSTEM 10 >> > Please do scan these! It is hard as hell getting info on The Source > and also on Dialcom! Yes, I definitely plan to transcribe them. There is potentially some copyrighted material here but I think I can just excerpt that and still include all the rest of the login process, etc. Still, would be nice to get the terminal itself working and see what's in the ASR's bubble memory, assuming that's still operational, so any ideas people have would be appreciated. -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- mouse, n: A device for pointing at the xterm in which you want to type. ----

2 years, 1 month

General Data? Computer Equipment Auction - GSA

by mark.kahrs＠gmail.com

The LSSM is very interested in this machine for public display. It would complement the museum's collection of PDP-11s and other 16 bit machines.

2 years, 1 month

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test-drb March 2022