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Peripherals available in Dorset, England : Free to a Good Home

by Martin Bishop

Folks The following job lots are available as described but untested, stored in the attic / house since last use : UMMV Lot A : Matsui B&W 13" 1420T SIL UHF & Scart 230V (may be useful as a retro monitor esp as exhibit) [operable when last in service ~?] Lot B : Samsung CLP-350 A4 Color Laser Enet 230V - contains consumables, level unknown - very streaky when last used + CLP-R350A Imaging Unit + CLP-W350A Waste Bin + CLP-C350A Cyan toner + CLP-Y350A Yellow toner + CLP-M350A Magenta toner [consumables BNIB] [operable but streaky when last in service ~2015] Lot C : Samsung CLP680 A4 Color Laser Enet 230V - contains consumables, level unknown - motion fault when last used "A1-4112" + CLT-K506L Black toner [consumable BNIB] [defective "A1-4112" when last in service ~2022] While these are on the margins of classic, I'm happy to give the community first refusal on a free to a good home basis. Collection needs to be no later than next Thursday 8 December. If firm collection arrangements have not been made by CoP Sunday they will be offered on Gumtree ... If they are still here after Thursday, they may go wheee. Apologies for the short notice. Replies to ftagh(a)janefield.org will be regarded as offers. Collection offers will be considered in the round, but the early bird is likely to have an advantage, accepted offers will be honoured until the agreed collection time passes, thereafter the acceptance will lapse and they will be back in play. Martin

3 years, 4 months

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RIP Fred Brooks (1931-2022)

by Tomasz Rola

As the subject (and wikipedia) say: https://en.wikipedia.org/wiki/Fred_Brooks -- Regards, Tomasz Rola -- ** A C programmer asked whether computer had Buddha's nature. ** ** As the answer, master did "rm -rif" on the programmer's home ** ** directory. And then the C programmer became enlightened... ** ** ** ** Tomasz Rola mailto:tomasz_rola@bigfoot.com **

3 years, 4 months

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Re: Fwd: Philips P2000C carrying strap

by Smith, Wayne

Found an ad from 1984 - poor resolution but gives you an idea of what the strap looked like. -W https://photos.app.goo.gl/NG7kCK4qHyDgNKxb6 Date: Sun, 25 Sep 2022 16:25:59 +0100 From: Tony Duell <ard.p850ug1(a)gmail.com> Subject: [cctalk] Fwd: Philips P2000C carrying strap To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk(a)classiccmp.org> Message-ID: <CAHkUCCzHdS2ayzu=pguLaj_KEHqGv-TZxE8Bv2ap8hUKL=CYDw(a)mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Does anyone have a Philips P2000C CP/M luggable with the carrying strap? I will be restoring such a machine in the near-ish future and mine is lacking the strap. Clear photos of the end fittings that slot into the machine, the dimensions of them, etc would be a great help in making something up. -tony

3 years, 4 months

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Guidance on repairing Dec PDP 11 System

by Devin D

Greetings, Been a while since i have posted here. I have several PDP11 systems and peripherals. I picked the original lot of a system 34 and related tech in Miami FL a couple years back, and have since found several more pdp 11/34 machines, and a pdp 11/05, 11/85, and others. It has been a goal to get the original PDP 11/34 system up and running, however my job schedule kept getting in the way of my repair efforts, making it easy to loose track of where i was at with the repair progress. Thankfully i no longer work in a datacenter in a 10 hour overnight shift, so it should be much easier to devote my time to this repair. I am looking for advice to get the 11/34 system up and running. I have started to put together a site to document my progress, to stay on track with the repair effort. The system has 2 rl02 drives, and an attached 9 track tape drive. I had worked to repair a power supply issue at first, there was a problem with the main transformer, as well as one of the smaller voltage "bricks". Thankfully i have many systems and i was just able to swap in the needed working parts. So this is about as far as I got, I had a minimal config of the 11/34 machine running, with not much more than the cpu, and a serial card to talk to attached terminal. Power supply works, and i was able to toggle in programs from the front panel to output characters to the attached terminal. I believe the next logical step was to try and attach the rl02 controllers, and see if the disk packs still have working installs of RSX installed. I am not sure how to proceed with this though. I have mainly been following the advice of Paul Anderson, who has been a godsend in regard to advice and guidance with getting these old systems fixed up. I hope that if i keep a log of the repair effort on my site, it will allow me to pick up where i leave off with the repair much more easily. So that is the present condition of the machine. Good power supply, can toggle in simple programs to print to the attached terminal. Any advice on how to proceed is much appreciated. I Need to get an itemized list of what hardware and cards i have on hand, and post that here so its understood what i have. Thanks, Devin D.

3 years, 4 months

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Box of SCSI stuff

by Van Snyder

I have a box of SCSI stuff that I'm no longer using. PCI adapters (Adaptec, Symbios) Cables -- 68-pin, 50-pin Centos, 50-pin Mac-Centos, 50-pin ribbon cable, .... Terminators Yours in exchange for a PDF of a USPS flat-rate box shipping label. Everthing might fit in a medium flat-rate box, but just to be sure send a PDF for a large flat-rate box. Van Snyder

3 years, 4 months

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Identifying a Failed Diode in a Rainbow H7842 Power Supply

by Rob Jarratt

The H7842 PSU in my Rainbow failed yesterday. At first the machine just powered down and there was a slight burning smell, I wasn't next to the machine when this happened, so I didn't see or hear anything to tell me where the problem might be. Not being sure if there was a short in the machine or a problem in the PSU, I disconnected the fans, FDD and HDD and, probably foolishly, I applied power again to see if the machine would work. At this point there was a bang and a flash in the PSU. On opening up the H7842 power supply I found that one of the transistors had completely disintegrated. It looks to be the main switching transistor, here is a picture of it: https://rjarratt.files.wordpress.com/2022/11/img_20221120_165850.jpg. I have identified a source for this transistor, but if anyone can suggest a modern replacement that would be useful too. However, that is not my main problem. Given that before the transistor blew up there had clearly been another failure somewhere else, I tried to find the original failure. There were no obviously damaged parts, so I just probed around near the transistor for any parts that were open circuit or short circuit. I found a diode connected to the base of the transistor that appeared to be short circuit. So, I decided to lift one end to check it. As I de-soldered one of the leads, the diode broke in two. So clearly the diode was either damaged by the failure of the transistor, or it was the cause of the failure. This is the diode: https://rjarratt.files.wordpress.com/2022/11/img_20221120_165913.jpg. I can't quite make out the markings on the diode to know what to replace it with. I think it says "D610". Would that be the right designation? If so, can anyone suggest a suitable replacement please? The diode seems to connect an inductor to the base of the switching transistor and the collector of the transistor is connected to a transformer. Should I be looking for other failed parts? Not sure if the diode failed first and then caused the transistor to fail? Or if something else has failed which caused these parts to fail? I do know that there are no shorts in the Rainbow itself, because I have a spare PSU that still works fine in the same machine. I blogged this here (it repeats most of that I have said above): https://robs-old-computers.com/2022/11/20/dec-rainbow-h7842-power-supply-fai lure/ Thanks Rob

3 years, 4 months

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To cctalk owner: There's a problem subscribing

by Toby Thain

Clicking Subscribe goes to a Not Found page. I found this out because I'm trying to subscribe with a new email address. --Toby

3 years, 4 months

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Help! Mentec and GRC DEC compatible manuals not in usual places...

by Robin Downs

Hi and thanks for reading... I am on the way to getting a small Q-Bus PDP11 up and running (I used to work on and repair then in the 1980s) and have some boards and a chassis now, but I cannot find any documentation for a couple of less common boards I have got - any help would be greatly appreciated - but I have looked in the usual places... The main issues are: Mentec M70 CPU - There are jumpers for serial port config and speed.. I have got a glossy leaflet for it but no jumper info.. GRC MLV11 - two serial lines and 128KB memory, but configured with switches - lots of switches... Also is anyone has any old Q-Bus parts in the UK (particularly any Baydel parts) that are looking for a good home, I would love to hear from you! Thanks for reading - any help or info much appreciated! Regards, Robin Downs Email: rdowns(a)radix.co.uk<mailto:rdowns@radix.co.uk>

3 years, 4 months

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Holmes Engineering CP/M

by Mike Loewen

I'm still looking for a copy of CP/M for the Holmes Engineering VID-80 board for the TRS-80 Model III. A manual would be helpful, as well. Mike Loewen mloewen(a)cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/

3 years, 4 months

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digital group's Richard Bemis

by Whitney Scharer

Hi Brad, I just came across your post from last year about my father, Richard C. Bemis. He passed away in June. I wish I knew more about the digital group and would love to see the video or article you are working on. I can also fill you in on what my dad did after dg. Thanks, Whitney ___ Whitney Scharer *The Age of Light* Order today from Bookshop.org <https://bookshop.org/shop/whitneyscharer> or Amazon <https://www.amazon.com/Age-Light-Novel-Whitney-Scharer/dp/031652414X/ref=sr…> whitneyscharer.com <http://www.whitneyscharer.com/> | @wscharer <http://www.twitter.com/wscharer> | instagram.com/wscharer

3 years, 4 months

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