test-drb September 2021

test-drb@ccmp.vtda.org

125 participants
76 discussions

by gcnielson＠yahoo.com

I was digging through the internet and found a post where a 3803 was posted for sale, would there happen to still be one available?Preferably a model 2 Thanks,gcnielson at yahoo.com

2 years, 7 months

Data General NOVA 2/10

by ccth6600＠gmail.com

I just started working on a Data General NOVA 2/10 which is in quite reasonable cosmetic condition, but has a number of problems. The system comes with 8 kwords plus 16 kwords of core boards and a "Cassette I/O" board and the CPU board. After reforming the "man sized" caps and verified the power rails I took a leap of faith and plugged in the CPU and the 16 kword core board. I managed to deposit a few bit patterns and read back mostly what I deposited. After a few power cycles I could no longer deposit values and read back what I deposited. I also noticed that a 30 Ohm resistor rated at 3W which previously got quite warm now stayed cold. That PCB area around that resistor has cooked in the past and has changed colour - not dramatic, but it obviously got quite hot in the past. Unfortunately I didn't find a good schematic specifically for the Nova 2/10. There is one for the Nova 2/4 up on Bitsavers, but it is hard to read and does not cover the NOVA 2/10 which is not quite the same as the NOVA 2/4. For example the power supply is completely different. Until now I have been spoiled with quite decent DEC PDP-8/e documentation and would be surprised if Data General did not provide a similar level and quality of documentation. Maybe I am looking in the wrong place. Thanks Tom Hunter

2 years, 7 months

FTGH: 19" Intergraph Monitors

by cube1＠charter.net

I have an Interpro 2020 and a couple of HUGE 19" inch Intergraph monitors. Frankly they are pretty lousy (fuzzy, not all that luminescent), heavy and awkward. Free to a Good Home - cables included. But I won't ship them, though one could pay someone to crate them up and ship them. I really don't want them around, and so I just converted my Interpro 2020 to use LCD flatpanels with a DB5w5 to VGA cable. You can read more about my new cable setup for this machine, and see one of the old monitors, at: https://www.computercollection.net/index.php/unix-workstations/#interpro2020 JRJ

2 years, 7 months

Identifying LSI Logic IC

by kylevowen＠gmail.com

Can anyone identify this IC? https://imgur.com/a/CU7Cn8z This is from an Omega VLF receiver. I don't see many custom parts within this unit, but perhaps this is one? Thanks, Kyle

2 years, 7 months

PDP 11/40 for sale, Paris, France

by stephane.tsacas＠gmail.com

Hi, If you're interested, contact me directly. It was in my apartment for years, I had to move it to the garage, and I don't like the idea of leaving it there for the winter. It's a PDP11/40 in a DEC rack. It was in working condition when I got it, only the memory card had a problem (1 capacitor has been ripped off), but reading/writing from/to the registers was working. No need to say that you have to arrange shipping ! Thanks, -- St?phane

2 years, 7 months

Lecture: The evolution of TECO and EMACS – hands-on demo, 2021-09-11, 19:00

by stueberahoo＠yahoo.de

Hi all, you're invited to the Update computer club[0] public lecture series "Updateringar"[1]! When: 2021-09-11, 19:00 CEST Where: https://bbb.cryptoparty.se/b/upd-0mo-m2u-aq8 The evolution of TECO and EMACS ? hands-on demo The Emacs text editor has long been an important tool among programmers, and has a long and rich history. I will talk about the development of the TECO and Emacs line of editors throughout history. The emphasis is on practical demonstration of programs found through software archaeology. True to form, the bulk of the presentation will be broadcast using ancient technology. Lars Brinkhoff (ICtech) The lecture is free and open to everyone. Upcoming: 2021-10-09, 19:00: Update Computer Club: History and not-so-certain future. Pontus Pihlgren (Update) Don't want to miss upcoming events? Subscribe to our low-traffic announcement list by sending a mail with the body "subscribe announce" to majordomo at update.uu.se! Hope to see you there, Anke [0] https://www.update.uu.se/index_eng.html [1] https://www.update.uu.se/wiki/doku.php/projekt:updateringar

2 years, 7 months

Anyone Have the H9642 Enclosure Maintenance Manual EK-187AA-MG

by robert.jarratt＠ntlworld.com

I have looked on Manx and on Bitsavers and I don't see it there. Thanks Rob

2 years, 7 months

VAX4000 VLC diagnostics/console

by binarydinosaurs＠gmail.com

Hi folks, I'm testing a little BlueSCSI adapter (BlueSCSI <https://scsi.blue/>) which while being aimed at 68K Macs should also work as an 8 bit target for older VAXen, it's a newer cheaper SCSI2SD solution and I should point out it works as intended on a Mac Plus so the module itself is fine. Nobody appears to have tested on small VAXen yet so tonight I dug out my VLC to give it a go. Powering up with nothing attached apart from an MMJ/H8571 cable I get nothing on the console, I'm using PuTTY via a genuine COM1 port on a PC which is one level above what I used last time I powered the machine up (FTDI USB adapter to a laptop). Diagnostic LEDs cycle through the tests and end up at '1111 0011' which according to the manual is 'entering the console program'. Clearly the DALLAS has passed the TOY tests, but if it's not happy would that stop the console displaying? It doesn't matter how I set S3, next step I guess is to hook it up to a 'proper' VT. Cheers, -- Adrian Graham Owner of Binary Dinosaurs, the UK's biggest private home computer collection? t: @binarydinosaurs f: facebook.com/binarydinosaurs w: www.binarydinosaurs.co.uk

2 years, 7 months

Replacement for Foam Filter for PDP 11/24

by robert.jarratt＠ntlworld.com

Another query. The foam filter that sits in the front of my 11/24 CPU is clearly badly degraded and needs to be replaced. What do people replace this kind of stuff with? I guess it mustn't be too fine, this mesh seems quite coarse. https://rjarratt.files.wordpress.com/2021/09/1124-front-panel-2.jpg Thanks Rob

2 years, 7 months

Capacitors on M8722 Board

by robert.jarratt＠ntlworld.com

I have a PDP 11/24 which I hope to power up soon. The last time it had power I noticed a bit of a burning smell which I failed to track down. However, I did notice one capacitor on a memory board has a strange appearance, almost as if there is some corrosion under the surface, it doesn't seem to be bulging though, except along the top, but if it is bulging it is very bumpy. I have a picture of it here: https://rjarratt.files.wordpress.com/2021/09/wp_20210904_10_15_28_rich.jpg. It is marked 47uF 30V, but it is also marked 20v as can be seen in the picture. I lifted it to measure its capacitance and ESR. It measures about 80uF and the ESR seems OK. I am unsure whether to replace it, and if so what voltage rating should I replace it with? I don't understand if this is a 30V rated capacitor or 20V. It seems that Unibus has some 20V signals, so I guess 20V might be right? I don't think 30V or 20V parts exist though, so I would need to get 35V or 25V. Maybe the voltage rating isn't too critical? Any advice? Thanks Rob

2 years, 7 months

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test-drb September 2021