test-drb February 2021

test-drb@ccmp.vtda.org

113 participants
93 discussions

IBM AS/400 and HP scope for sale in the UK

by alsilisk＠icloud.com

Dear all, I have been looking to downsize a bit in recent times and am looking to get rid of an IBM AS/400 9404 F10 and an HP 175a oscilloscope. As these things are large they are pickup only in the Petersfield area. I cannot guarantee either work. Although the scope comes with spares and does show some signs of life. It is not my area of expertise and it is probably going to need a full rework, it being from the 60s. The AS/400 is a similar story although will probably be a much simpler task. Send me an email if you are interested in either one of them or want pictures or have questions. I also realise it is lockdown, but if you send me a line now I can hold them for you rather than them being scrapped. Thanks, Al

3 years, 2 months

ENIAC 75th Anniversary Celebration

by blstuart＠bellsouth.net

This evening begins a series of events celebrating the 75th anniversary of the unveiling of the ENIAC at the University of Pennsylvania.? On the 11th and 18th, the Philadelphia Venture Cafe will be hosting virtual round tables with a number of us who have some connection to the ENIAC and Philadelphia technology.? Included among the people present will be: - Bill Mauchly and Chris Eckert, sons of the ENIAC creators - Bill Mensch, part of the 6502 engineering team - Kathy Kleiman, producer of the ENIAC programmers documentary (And yes, I'll be there for anyone who wants to get nerdy and talk about the technical aspects of the machine and its programming.) Monday, the 15th is the day of the anniversary, and there will be a full day of webcasting.? Starting at 10:30 EST, UPenn will be holding a mini-symposium in recognition of the ENIAC.? Then at 3:30 EST, Unisys will be webcasting an ENIAC celebration video that includes a number of panel discussions, as well as clips from early newsreels, and happy birthday wishes >from the various locations housing ENIAC artifacts. More details and links to all the events can be found here: http://www.eniacday.org/events/ BLS

3 years, 2 months

RX02 DMK image to raw tool?

by david4602＠gmail.com

On 2/8/21 1:00 PM, Mattis Lind wrote: > This is highly annoying. Back in 2015 I did exactly this and now I have > forgotten how. > > I dumped a set of RX02 disks with catweasel into .DMK and now I want a raw > sector image to be able to test them with SimH. > > What is a good tool to use? I have some faint memory of glancing through > hexdumps of .dmk files. Perhaps I did something myself using dmklib by Eric > Smith? Don't really remember, unfortunately. > > But surely someone else has already done this, right? > > /Mattis I wrote my own, not knowing where another one lived. I happen to think in Java, so that's what it's implemented in. Description is here: https://github.com/RetroFloppy/transformenator/wiki/Utility-Functions#dmk2r… Code is here: https://github.com/RetroFloppy/transformenator/blob/master/src/org/transfor… The only thing of interest is the cw2dmk tool would read RX01 disks and "double" the data - so my tool will make an attempt to detect that and halve the data back out the other end. - David

3 years, 2 months

New pinion gears for plotters...

by geneb＠deltasoft.com

For those of you with the Atari & Commodore pen plotters that have broken pinion gears, there's now a guy making new ones in brass: https://www.soigeneris.com/alps-printer-plotter-mechanism-pinion-gears g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://scarlet.deltasoft.com - Get it _today_!

3 years, 2 months

Mystery NCR disk pack

by p.gebhardt＠ymail.com

Hello list, there is an NCR-labelled disk pack offered in the bay with a geometry that I've never come across before: https://www.ebay.com/itm/353379280282 It seems to be a 14" pack with three platter and six recordable surfaces. The platters themselves are quite thick and the distance between the platters is quite wide compared to the IBM 1316 and 2316 type standards. Does anybody know if this is really an NCR development or if it is a rebadged pack from another manufacturer? Any hints to solve this mystery is much appreciated :) Best regards, Pierre PS: I wonder if the seller describing the party dog is describing himself, but partying seemed to be an important part of his life ;) ----------------------------------------------------------------------------- http://www.digitalheritage.de

3 years, 2 months

resistor packs for terminating SCSI bus inside Exabyte 8020

by nw.johnson＠ieee.org

Hi all, I wonder if anybody has one with the terminators installed that can read off the p/n for these SIPs The manual says they are 8-pin 7 resistor 220/330 ones, but that is not possible! To put 7 resistor pairs to 220 and 330 you need a 9-pin, unless you have one resistor SIP for 220 and another for 330!? But there are 2 so that leaves an odd number! The sockets are 9-pin.? I have yet to find any 9-pin ones on digikey cheers, Nigel -- Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 nw.johnson at ieee.org

3 years, 2 months

Apple ][+ ic

by david4602＠gmail.com

On 2/10/21 1:00 PM, John Many Jars<john at yoyodyne-propulsion.net> wrote: > So, I have an Apple ][+. It is missing an IC at location a3 on the > motherboard. > > I don't know why. it used to work... I think my mind is going. I have no > memory or removing it. Anyway, I need another one. The board is marked > 74166. > > Can I put any shift register IC with a similar part no, like this one: > > 74166PC | FAIRCHILD | IC DIP-16 Shift Register (icompplus.com) > <https://www.icompplus.com/en/integrated-circuits/24400/74166PC> > > in there, or ? > > Thanks, > > mark aka john I have a mobo that has that very part (Fairchild 74166PC), so it's a good bet it'll work. - David

3 years, 2 months

Part# request: TK70 eject switch

by cz＠alembic.crystel.com

Working on fixing a pair of TK70's here to speed up my backups. The TK50 is fine on a TQK70 controller (it streams perfectly) but I am coming close to filling a tape. I've managed to assemble a working TK70 out of two unhappy ones, but to fix the other I need to replace the eject button switch. The plastic/rubber on it has turned to the usual goo. Does anyone know the part number for that switch? Taller than a usual SMD button switch, so a stock one won't work. I could take it apart but that would be a kludge. Thanks!

3 years, 2 months

APL\360

by paulkoning＠comcast.net

I was just poking around the computerhistory.org website, searching for Knuth stuff. The second or third hit when I search for "Knuth" is this one: https://computerhistory.org/blog/the-apl-programming-language-source-code/ . It's not just about APL, it actually has a downloadable copy of the source code. And it points to an executable version, apparently a packaged up Hercules running that code. Nice. I'll have to give it a try. paul

3 years, 2 months

Digitalker 54104 IC

by brain＠jbrain.com

I suspect the answer to question #1 is no, but thought I would ask. 1) Anyone happen to have a known working Digitalker 54104 IC they are looking to trade for some cash that does not involve me selling an arm or a leg :-)? 2) Barring that, anyone have a known working Digitalker-based unit that might be able to pop in a suspected non working Digitalker IC and test? I have a Jameco (yep, the parts firm) manufactured Digitalker unit here called the JE-520 that is my original unit.? It suffered some ROM bit rot long ago and was not working, but I acquired the ROMs a while back to repair the unit. Now, though, as I pull it out for another project, it seems to be misbehaving.? It's like "address bit 1" on the input commands is acting up.? For instance, word 48 is "zero", and 49 is "one", but zero will be followed by "three" and then "zero" and then "three" as one sends values 48,49,50,51 to the unit.? I'm working to confirm the bit 1 on the cable to the PC is not bad, but initial efforts point to it being the IC. Jim -- Jim Brain brain at jbrain.com www.jbrain.com

3 years, 2 months

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test-drb February 2021