test-drb

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101090 discussions

by jnc＠mercury.lcs.mit.edu

Anyone want a KK11-A: https://www.ebay.com/itm/275173894774 US$200 sounds like a lot, I know, but KK11-A'S and FP11-A's are going for that much; an FP11-A just went for US$250. And KK11-A's are rare; this is he first one in a while. Noel

4 years

Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

> From: Rob Jarratt > I suspect some of the other cards that were in the machine might do the > necessary termination stuff. Different answers for each part of the functionality. 1A and 1C fundamentally have be at the end of the bus, physically. So, unlikely; since _other_ cards aren't, generally, designed to go there. 1B could be anywhere, but I've basically never seen anything but a CPU or a terminator with 1B functionality - probably in part because the same physical components uually do both 1A and 1B. (Oddball exception: M981 UNIBUS jumper, in the -11/40 - but that's 'sort of' part of the CPU.) 2, yes. E.g. the KT24 UNIBUS map has sockets to hold bootstrap PROMs. (Compatible with the M9312's.) Others, too; e.g. the KTJ11-B UNIBUS adapter (although that is not seen in an -11/24). Maybe others, but I can't recall off the top of my head. Noel

4 years

Testing H745 Regulators

by robert.jarratt＠ntlworld.com

I am trying to test a couple of H745 regulators with a DC bench PSU and I am having some problems with testing them. My bench PSU is a twin unit so I can supply the +15V required as well as the "AC" input using 20VDC from the other half of the bench PSU. The problem is that I don't think the bench PSU can supply enough startup current to allow the regulator to run. It can only supply 5A max. I have seen with the H744s that if I put too big a load on them, then they can't start because of the heavy startup current required. I can start them with a lower load and then add load once the regulator is running without breaching the current limit of the PSU. With the H745s I have tried reducing the load to see if I can get them to start, but a 10R load appears to be too much and the regulators draw the full 5A without outputting -15V. I have two H745s, both exhibit the same behaviour. I suppose they could both have the same fault, but I am inclined to think that perhaps they need a higher startup current than I can supply. Can anyone confirm this? Thanks Rob

4 years

ID these DEC floppy disks

by cz＠alembic.crystel.com

Hey all! While going through floppies I found these and was wondering what they were. Only clue in Google was someone asking in 1997 same thing. BL-T540B-M1 CZUFDB1 USER TESTS BL-T541B-M1 CZXD1B1 FIELD SERVICE TESTS 1 BL-T542B-MC CZXD2B0 FIELD SERVICE TESTS 2 BL-T565B-MC CZXD3B0 FIELD SERVICE TESTS 3 BL-T583B-MC CZXD4B0 FIELD SERVICE TESTS 4 Any ideas? The first one does not have a write protect tab, the others do. There is also one other disk I found CZMX4E0 Micro 11 Maint RX50 4 On this one the write protect flag was torn off (was on from factory and removed) C

4 years

HP 2100S Power Supply Disassembly Tips

by derschjo＠gmail.com

Hey all -- I've had this HP 2100S mini sitting on the bench for a bit, waiting, and I wanted to go through the power supply and test/reform the capacitors this past weekend. The processor service docs cover getting the supply out (which is slightly cumbersome) and I have that step done. But neither the processor docs nor the power supply service docs seem to cover how one disassembles the supply itself. (Has a really thorough guide to how the thing works though, that I'm hoping I won't actually have to use anytime soon.) There are a lot of parts in this unit, and I'm not seeing a method to the madness. The capacitors are fairly easy to *get to* but actually removing them for testing / replacement seems to be another matter entirely. Anyone out there done this before and have any advice? Thanks! - Josh

4 years

Red Hat Linux 7.2 for Alpha

by p.gebhardt＠ymail.com

Hi Ben, >? I can't seem to find this anymore.? I have seen a few mentions that there is a "wrapper" installer that is necessary to install 7.2 on an ES47/ES80 >machine, and I'm hoping that it was archived or mirrored some place... Back then in 2016, I also looked for these images for my ES80 machine on the HP site and tried to find ftp mirrors, but all I found were broken links. I would be happy, too, if anybody has a copy of these installation sets. Cheers, Pierre

4 years

VCF Swap Meet in Wall, NJ Sat, Feb 26 - Vintage Computers, Amateur Radio, TV, Radio, other Tech

by jeffrey＠vcfed.org

*The vintage Computer Federation will be having their 3rd swap meet.* *Saturday, February 26, 2022* *8AM to 2PM* *ADDRESS*: *Indoor swap Meet* InfoAge Science and History Museums (Camp Evans) 2201 Marconi Road, Wall, NJ 07719 Buildings 9010-D, 9032-A, 9001 *GPS location*: Google Maps <https://goo.gl/maps/YiEnhJAtffHTnfn8A> *Satellite Map*: *Street Map*: *EMAIL*: swapmeet at vcfed.org *PHONE*: 732-722-5015 *Flyer:* 2022-VCF-Swap-Meet-Flyer <https://vcfed.org/wp/wp-content/uploads/2022/02/VCF_Swap_Meet_2_26_2022_LQ_…> *Website*: https://vcfed.org/wp/vcf-swap-meet/ *VENDOR COST* is per space. First space is $20, each additional space is $10. This time it is an *indoor* swap meet. *Bring your own table!* Table isn?t required, but recommended. A space is considered a 6 by 3 foot area (the general size of a table). *Vendor setup at 7AM.* *FREE GENERAL ADMISSION!* *SEND PAYMENT TO*: paypal at vcfed.org (FRIENDS AND FAMILY OPTION) Write in the note section: [your name] VCF Swap Meet 2/26/2022 Number of spaces: *Click HERE for Swap Meet Vendor Signup* <https://docs.google.com/forms/d/e/1FAIpQLSfplnIROL-TTJ3qNkIo45mTelGNY3QCaFi…> * Reservation doesn?t guarantee sales. * The Vintage Computer Federation is only providing a space, vendors must bring their own tables. * In case of inclement weather, money paid will be refunded. * All items that you bring must be taken with you. No items are to be left behind. * Bathrooms on site * Limited food and drink options available. The same info can be found here: https://vcfed.org/wp/vcf-swap?meet <https://vcfed.org/wp/vcf-swap-meet> *EMAIL*: swapmeet at vcfed.org *AFTER THE SWAP MEET, COME VISIT OUR VCF MUSEUM @ INFOAGE!* We are open from 12PM to 5PM: https://vcfed.org/wp/vcf-museum The Vintage Computer Federation Museum is located nearby the swap meet and is part of InfoAge Science and History museums. InfoAge and VCF Museums are open every Saturday, Sunday and Wednesday from 12PM to 5PM InfoAge museums: infoage.org.

4 years

Red Hat Linux 7.2 for Alpha

by ben＠huntsmans.net

Hi guys- Is anyone aware of an archive or mirror of HP / Compaq's Red Hat Linux 7.2 for Alpha download site: ftp://ftp2.compaq.com/pub/linux/RedHat/7.2-alpha/release-isos/ And the update site: ftp://ftp2.compaq.com/pub/linux/RedHat/7.2-alpha/updates/ I can't seem to find this anymore. I have seen a few mentions that there is a "wrapper" installer that is necessary to install 7.2 on an ES47/ES80 machine, and I'm hoping that it was archived or mirrored some place... Thanks in advance! -Ben

4 years

DECTape head problem

by go＠aerodesic.com

In debugging my DECtape interface lashup, I found that one of my head has two open windings.? Specifically, one channel has an open 'ground' with the other two lines apparently the full winding of the channel.? The second channel failing has no continuity between any of the three lines.? I have tested the other head and it has all the requisite continuity so I'm hoping I can at least get a single spindle running. Visual inspection of the head 'suggests' it might be caused by the age-old 'wire stress' of being captured within a polyester resin and then finally snapping due to internal stress.? I see lots of internal stress cracks on this head so I'm probably toast on this one. Are there documents on how the heads are made?? I.e. number of turns of number X wire; cap of X micros etc.? I'm not (yet) seriously entertaining the idea of rebuilding this head, but it looks pretty low tech.? These heads are Western Magnetic heads without a model number (only serial number 19976 - don't know the other head S/N as I haven't removed it yet.) And the look to be hand made... Has any ever attempted repair of one of these? -Gary

4 years

Varian 620/L backplane netlist?

by mark.kahrs＠gmail.com

I realize this a rare bird indeed, but would anyone just happen to have a Varian 620/L backplane netlist hanging around? Unless I missed it, the schematics on bitsavers do *not* have it.

4 years

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