test-drb June 2014

test-drb@ccmp.vtda.org

187 participants
157 discussions

TU58 tape formatter (was Re: rebuilding DC100A cartridges?)

by shadoooo＠gmail.com

Hello. I have a VAX730 with both TU58 drives destroyed (capstan melted, need replacements). I also have a bunch of cassettes, but unfortunately all seem to have problems with the bend and/or bad spots on the tape. Possibly I would try to replace the broken bands (if I find a source) and/or replace the magnetic tape when damaged (I was thinking to try with audio cassette tape, don' t know if metal oxide high density tape could be good for it). Anybody has some information about the coercivity of original DEC TU58 tape? One problem indeed is the need of reformatting the tape, but: if I can emulate the TU58 drive using a serial, would it be possible to send raw commands to the drive using the serial and a PC? Andrea PS-If possible, some good-condition cassette would be very useful to me too. I'm located in Italy.

5 years, 11 months

Does anyone have docs for a Ventel brand MD212-plus modem?

by ethan.dicks＠gmail.com

Hi, All, A friend of mine just returned a modem he got from me decades ago, a Ventel MD212-plus. It's an early-1980s non-AT-command-set autodialling modem. The settings are adjusted via a pair of 10-pin DIP switches accessible from the back. I've checked the web and bitsavers. So far, all I've found is some old Usenet articles and a couple of pictures, but no manual or jumper guide. One "feature" is that it lacks a modular jack to plug into the phone system. Fortunately, my friend kept the proprietary DA15 cable. I've never seen that choice of connectors on any other modem. Does anyone have any Ventel docs? Thanks, -ethan

7 years, 9 months

Digital archiving tools

by wmaddox＠pacbell.net

Many of us maintain large collections of bits that we'd like to preserve over a long time, and distribute, replicate, and migrate via unreliable storage media and networks. As disk sizes (and archive sizes) have increased, the probability of corruption undetected or uncorrected by the mechanisms normally built into disk drives, network protocols, and filesystems has increased to a level that warrants great concern. I would be interested to know if there exists an archive format that has the following desirable properties: 1) It is well-documented, and relatively simple, to facilitate its implementation on many platforms present and future. 2) It supports some degree of incremental updating, but need not be particularly efficient about it. An explicit compaction operation is preferable to an overly complex format. It is adequate to use append-only strategies appropriate for write-once media. 3) Insertion and extraction of files, copying of the archives, and other archive-manipulation utilities support end-to-end verification that identical bits have been stably recorded to the media, bypassing or defeating platform-level or hardware-level caching mechanisms. Where this is not possible, the limits must be carefully delineated, with some basis for determining the properties of the platform and certifying reliability properties where possible. 4) The format should provide for superior error detection capability, designed to avoid common failure modes with mechanisms typically used in hardware. For example, use a document-level cryptographic checksum rather than a block-level CRC. 5) The format should include a high degree of internal redundancy and recoverability, say, along the lines of a virtual RAID-array. Just as biological organisms constantly correct DNA transcription errors, the idea is to have a format that is robust across long-term exposure to imperfect copying and transmission channels. Does anything like this exist? --Bill

8 years

Scraping DEC Equipment

by dm561＠torfree.net

----- Original Message ----- > Date: Sun, 22 May 2011 22:56:32 -0500 > From: Daniel Seagraves <dseagrav at lunar-tokyo.net> > Subject: Re: Scraping DEC Equipment > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: <C7A98127-DFF4-41B1-A6AF-5DFCA234D286 at lunar-tokyo.net> > Content-Type: text/plain; charset=us-ascii > > I need a tractor feed assembly for a LA100, are the ones on the 120 > compatible? ----- Reply: Apparently not, but I might have one for an LA100. mike

8 years, 5 months

Tektronix 4404 servcie manuals needed

by g-wright＠att.net

I would like to get a Tek 4404 computer going but lack any service manuals. The system turns on but has no curser on the screen. Has good power from the Power supply and heater is on in the CRT. Has a row of LEDs on the mother board. Does anyone know how to read these. - Thanks, Jerry

8 years, 5 months

Servant .953

by roger.holmes＠microspot.co.uk

On 7 May 2010, at 08:25, cctalk-request at classiccmp.org wrote: > > Message: 2 > Date: Thu, 06 May 2010 16:06:37 -0700 > From: Al Kossow <aek at bitsavers.org> > Subject: Re: Servant .953 > To: cctalk at classiccmp.org > Message-ID: <4BE34B7D.6060902 at bitsavers.org> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 5/6/10 2:23 PM, Fred Cisin wrote: >>> Al Kossow wrote: >>>> I am interviewing Andy Hertzfeld tomorrow, and had hoped to talk about >>>> Servant, but I can't find a copy of it around anywhere tonight. > > A huge thank you to Nigel Williams who forwarded a working copy of .951 five > minutes before Bill and Andy arrived. We spent an hour talking about MacPaint > and Quickdraw (Apple has finally given CHM approval to make the sources available) > then another hour on Alice, Dali Clock, Servant, Hypercard, and Magic Cap. Could you please clarify, the QuickDraw source is available for what purpose? Could developers modify it any include it in heir commercial 64 bit Intel applications for instance? Is the source Pascal, Assembler, C or something else? Roger Holmes, Director of Microspot who has a Carbon application which compiles with over 10,000 warnings about deprecated QuickDraw calls.

8 years, 5 months

Any word on the Multics revival front?

by madcrow.maxwell＠gmail.com

When Multics was officially released as free software a couple of years ago, there was a flurry of activity aimed at getting some sort of emulator up and running to run it. Did anything ever come of that or did folks just lose interest (or find out that the needed GE/Honeywell hardware was too poorly-documented to write an emulator of) Mike

8 years, 7 months

TSX Plus...

by lbickley＠bickleywest.com

After stating that I expected TSX Plus to be available generally to the collector community this week, I have had a number of folks request access to TSX plus via private FTP. Please be a bit patient and wait for me to post it to a new website I'm in the process of creating. I now have full agreement from S&H to generally release TSX Plus, COBOL, etc., to the collector community via a simple download. BTW: I have converted all of the original documentation, which was in HP print file format to PDFs for easier and more general use. Over time I will likely be able to release some of the utilities, etc. that S&H used internally with TSX plus. Some time ago S&H gave me all of their RL02 packs and a SMD drive with everything they had related to the PDP-11 version of TSX. (They have a current version of TSX for X86 systems which is NOT free and is NOT part of this release). Over time, there may be a project to scan the source listings and recreate TSX Plus source code. (The source listings are available on bitsavers.org (pdf/dec/pdp11/tsxPlus/listings/). Unfortunately, we are missing the MACRO definitions in the source listings. Some of us are working on that issue. (Note: All of the original PDP-11 source code was accidentally lost by S&H). I will also make available any software that other folks submit to me related to TSX on my website. Regards. Lyle -- Bickley Consulting West Inc. http://bickleywest.com "Black holes are where God is dividing by zero"

9 years, 2 months

docs or software for Quay 900 (uses Quay 90F/MPS board)

by spacewar＠gmail.com

Does anyone happen to have documentation, schematics, or software for the Quay 900? It's a system based on the Quay 90F/MPS single-board Z80 computer and two MPI double-sided 8-inch floppy drives. The drives are MPI part no. 77618022, apparently a 9406 variant but not listed in the drive manual on Bitsavers. I suspect the pinout is close to the SA800/850 pinout (industry standard), but I was surprised to find that none of the variants in the 9406 manual have a pinout similar to that.

9 years, 2 months

Source for IBM logic probe tips

by h.j.stegeman＠hccnet.nl

Hi, Who can help me with a source (not IBM) for logic probe tips used with IBM MST and SLT backplanes. See: http://home.hccnet.nl/h.j.stegeman/IBM_logic_probes.jpg Prefably the lower one (P/N 453826). Thanks for your replies. Regards Henk

9 years, 7 months

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test-drb June 2014