test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dittman＠dittman.net

I have a VT525 that I couldn't turn off. I took it apart and there's an adapter that connects the metal rod off the button on the front to the power switch inside. The adapter has crumbled and it feels like it was wax but it may have just been some plastic that has severely deteriorated. Before I try to work up some kind of replacement, has anyone already designed a 3D-printed replacement? I don't have a 3D printer but do have a friend that could print one for me. Otherwise, I'll see if I can come up with something. -- Eric Dittman

5 years, 3 months

9 track tapes and block sizes

by shadoooo＠gmail.com

Hello, I have a question about 9 track tapes and block sizes. What I know is that tape is subdivided in files by means of marks, and each file is subdivided in blocks of equal size. Programs like tar use a specific block size to create files on tape. However files can have different block sizes like bootloader file, installation dumps and root file system copy on 2.11BSD. Now suppose you find and unknown tape you want to preserve: using dd you could easily 1:1 copy tape files to hard disk files using a SCSI drive and Linux. But: how you know which block size is on the tape? Thanks Andrea

5 years, 3 months

IBM PC-DOS 2.10 explorations

by will.senn＠gmail.com

All, I've been delving into ancient IBM PC-DOS... 1.0, 2.0 and have landed on 2.10 as the experience I'm going to hang out with for a while. It's stable in QEMU and 86Box and I am able to run MASM 1.0, 2.0 and Pascal 1.0 and 2.0. 86Box is more true to old-school boxes, but qemu runs on my Mac, so I like using Qemu. But, Pascal seems to prefer 86Box, it prints weird characters in qemu w/writeln(), which is annoying, but I'm doing more assembly and BASIC at this point, so Qemu's emulation is sufficient. What I've got working: IBM PC-DOS 2.10 - seems to be working fine in both (installed to fixed disk) IBM Macro Assembler 1.0 and 2.0 - seems to be working fine in both (installed to fixed disk) IBM Pascal 1.0 and 2.0 - hokey in both, tricky about the floppy being present, regardless of debug fix, and doesn't like QEMU. QEdit 2.1 - works great in both (installed to fixed disk) I found some good books on BASIC, Pascal, and Assembly: Albrecht, 1990. Teach Yourself GWBASIC. (covers later BASICA sufficiently) Pardee, 1984. The Waite Group Pascal Primer for the IBM PC. (Great book) Metcalf and Sugiyama, 1985. Compute!'s Beginner's Guide to Machine Language on the IBM PC & PCjr. (Excellent book) Lafore, 1984. The Waite Group Assembly Language Primer for the IBM PC & XT. (Wordy, but good) Pretty much everything I've programmed works fine. Graphics stuff is better in 86Box where I can control the monitor that's attached, but no complaints. Some questions I have related to the exploration: 1. I'm curious if there are other folks out there doing similar stuff? 2. Most of the Assembly examples use DOS interrupt 21 for output. Is this typical of assembly programs of the time, or did folks use other methods? 3. I was able to find a lot of 5150/5160 and other manuals, but I couldn't find an IBM Macro Assembler 2.0 manual (there are plenty of IBM Macro Assembler/2 manuals, but those are for OS/2, not DOS). Does anyone know where I can find one online? 4. In y'all's view, what are the significant differences between IBM PC-DOS 2.10 and it's brother MS-DOS 2.x? 5. I'm thinking of moving on to 3.3 at some point, in your view, what are the advantages? 6. I'm happy to post here, but if y'all know of a more appropriate venue, please suggest it? Thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF

5 years, 3 months

Anyone want to part with a DEC MXV11-B (M7195) and/or M8012 (BDV11)?

by jnc＠mercury.lcs.mit.edu

> From: Chris Hanson > There's an MXV11-B (M7195) on its way to me. :) Wow, you've got a really good fairy god-mother! I've been trying to buy one on eBait for some time now (in part to have one to take a photo of for the CHWiki), and no luck - they always get bid up into the sky. And here someone has one for you! Life is unfair! Noel

5 years, 3 months

Thompson's Space Travel running

by lars＠nocrew.org

Hello, Ken Thompson's space exploration simulation Space Travel will now run on the SIMH PDP-7 simulator: http://sebras.se/space-travel-2.mp4

5 years, 3 months

Identifying mystery TI ICs (Motorola MDP-1000 investigation continues...)

by couryhouse＠aol.com

The making of this computer? perhaps explain why I never had someone wander in and talk about designing or building a MOTOROLA MINICOMPUTER ....Ed# On Monday, October 5, 2020 Bill Degnan via cctalk <billdegnan at gmail.com; cctalk at classiccmp.org> wrote: On Mon, Oct 5, 2020 at 1:10 PM Al Kossow via cctalk <cctalk at classiccmp.org> wrote: > On 10/4/20 11:13 PM, Josh Dersch via cctalk wrote: > > > Just made a minor breakthrough; a random usenet post suggested that the > > MDP-1000 was just a rebadged General Automation SPC-12, and so it is.? I > > suspect the internals of the unit I have (which is badged as an > "MDP-6650" > > on the rear) are a bit different than either the MDP-1000 or the SPC-12 > > (and I'm no closer to finding answers to my IC identification questions), > > but it at least gives me another avenue to explore... > > > > (Bitsavers has a few items: > > http://bitsavers.org/pdf/generalAutomation/spc12/) > > https://www.computerhistory.org/collections/search/?s=spc-12 Is this a case of not being able to find the correct TI or Motorola IC guide or is there something unique / OEM about this one?? I do have some late 60's early 70's IC guides of these manufacturers that I can check, original bound paper copies.? Please advise. Bill

5 years, 3 months

Identifying mystery TI ICs (Motorola MDP-1000 investigation continues...)

by derschjo＠gmail.com

More mysteries while poking at the MDP-1000. Spent some time this evening working out the rest of the signals on the power harness (I suspect inputs for an LTC circuit and a "power good" signal, as well as something connected to a relay on the backplane, probably related to power control). There are a lot of unidentifiable ICs on the main CPU logic board and on the backplane, mixed in with bog-standard 7400-series TTL. Curious if anyone has any ideas, as my searches and perusal of datasheets/databooks on Bitsavers have turned up nothing. These are all TI-manufactured ICs, 1969 manufacturing dates, with "SN48xx" and "SN63xx" part numbers (a few omit the "SN" prefix.) I'm wondering if these are just standard 7400 ICs with special codes; for example there are several SN4816's near the edge connector for the I/O bus, where a 7416 might (?) make sense, and from some basic probing and following traces I think the pinouts make sense. (Everything's conformal coated so it's a real bear to beep things out...) Any ideas? Thanks again, Josh

5 years, 3 months

ancient 5" SMD message

by aek＠bitsavers.org

5.25" SMD drives From: David C. Jenner <djenner_at_earthlink.net> Date: Tue Jun 24 19:28:00 2003 I have complete docs (User's Manual and Reference Manual, both very long) for both of the Seagate drives (the manuals cover both). And a stock of the 1.2GB drives, including power supply and cables. And QD33 Qbus adapters. I'll be glad to entertain offers for these offline, especially trades for PDP-11 equipment. Dave --- wonder if - he is still on the list - still has the manuals

5 years, 3 months

Sun SPARCstation LX boot from CDROM?

by chentsay＠yahoo.com

Dear Tom, Does your Sun workstation is functional and read QIC -150 cartridge? I have some old 3M 6150 cartridges that was created by Sun Sparc workstation in 2000. One those cartridges, I have some my personal files I like to get them. If you can you read those cartridges, I can pay some money for you? Chen Tsay

5 years, 3 months

Modcomp computers and documentation

by lyokoboy0＠gmail.com

Greetings everyone, it's Been a while since i posted here. I had picked up some modcomp minicomputers over the past couple years. A modcomp classic, with a nice front panel with binary swiches, similar to a pdp 11. There is a modcomp 32 as well, the machine boots from internal floppy drives. I was eager to pick up these machines, and save them from being thrown out. I picked up all of the documentation as well. Everything. A truckload of os information. I started to scan it all, but about 3/4 of the way through, my scanner broke. The 32 machine was not stored in climate controlled conditions before i picked it up, and is a bit more worn. It is designed to boot off floppys to load the microcode into the cpu... but the floppys... id be supprised if anything survived. Stored in bad conditions. The classic has internal microcode roms and will not have the same troublesome problem. I have been unable to devote the time and space to these machines as i had planned. I have been far too busy working at ibm, i am planning to shut down my side interests and focus on my dec pdp 11 stuff and ibm mainframe. I am looking to see if anyone would be interested in buying these. I spent a great deal getting them moved and keeping them in cool climate controlled storage, i am looking to see if i can get any offers and break even. Keep in mind, they are the size of a computer rack and heavy. I will post back with pictures soon.

5 years, 3 months

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