test-drb July 2016

test-drb@ccmp.vtda.org

190 participants
243 discussions

by lists＠loomcom.com

(n.b.: Sorry for the "wanted" spam from me. I think this is the last one for a while!) I have access to a friend's AT&T 3B2 Model 400 for exploratory and reverse-engineering work, but I would really like to get a system of my own. To that end, if you have an AT&T 3B2 you'd like to part with, please drop me a line. Happy to pay fair market prices, or consider some trades if you prefer that (I have a lot of DEC Qbus stuff) I'm also still looking for more documentation. I especially wish I had schematics, and any docs related to writing drivers. Anything that would be useful in documenting the 3B2 internals would be lovely. Thanks! -Seth

7 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, 11 months

Flex Disc options for the HP 9825

by curiousmarc3＠gmail.com

Probably a question for Tony's encyclopedic knowledge. I just scored two HP 9825, one a later "T" option and one "B" version with all the fixings (i.e ROM packs). They both seem to work save the usual tape drive which I have not gotten to yet. Both have the flexible disc ROM. What kind of discs can I hook up? I think the HP 9895 8" floppy would work. What about the HP 82901 5.25" floppy drive? How do I read/write program files from the disc interface? Marc Sent from my iPad

8 years, 1 month

UNIBUS/QBUS interface chips Was: Re: MEM11 update

by jnc＠mercury.lcs.mit.edu

> From: Pete Lancashire > Do you or someone have a list of all the Unibus bus chips ? I have seen the following bus interface chips used on DEC UNIBUS boards: Drivers: 8881 - Sprague, Signetics - Quad NAND Receivers: 380 - Signetics - Quad NOR 314 - Signetics - 7-input NOR 8815 - Signetics - 4-input NOR 8837 - National Semi - Hex receiver (aka Signetics N8T37) 8640 - National Semi - Quad NOR Transceivers: 8641 - National Semi - Quad transceiver The actal complete part number can vary depending on the manufacturer; e.g. the 8641's are usually DS8641N, from NatSemi, and the 380's are usually SP380A's or SP380N's. Where the basic number is not included (as with the 8T37 for the 8837) I have given it. The following chips have been used by DEC to interface to the QBUS, and I have seen many of the above chips (e.g. 8641's) used there too, so I think chips seen on one bus could be used on the other: Drivers: 7439 - Various - Quad NAND Transceivers: 2908 - AMD - Quad latching transceiver with tri-state output I _believe_ the following chips are also usable as UNIBUS/QBUS interface chips, but I'm not sure if I've seen one used there: Transceivers: 8836 - National Semi - Quad NOR 8838 - National Semi - Quad transceiver (aka Signetics N8T38) Quite a zoo! Noel

8 years, 1 month

tumble under BSD

by aek＠bitsavers.org

Out of curiosity, has anyone ever gotten Eric Smith's tumble pdf creation program running under any version of BSD? I ran into a problem porting it to OS X, in the way it used rewind() and was wondering if anyone else ran into that on other BSDs

8 years, 1 month

It's BASIC Week again!

by fozztexx＠fozztexx.com

I do a regular contest on RetroBattlestations called BASIC Week which is a sort of tribute to the days when it was common for programs to be published in books and magazines and people would type them into their computers. One of the neat things about distributing software through type-in listings is that there?s no need for working disk drives or tape drives, or to do complicated things like get a serial connection working and find a way to transfer files. If a computer has built-in BASIC just turn it on and start typing! Past programs have displayed vector graphics, silly text screen animations, and a couple of games. This time around the program is called Winchester Drive and the concept is to explore a mansion to see what you can find. I decided this time around to try out true sprites and made a version for both the Apple II and Commodore 128. I wanted to do a Commodore 64 version but couldn't find any line drawing routines written in assembly anywhere! I thought for sure in the last 33 years some book or magazine somewhere would have written a couple of simple routines to clear the graphics screen and draw some lines that you could POKE in and then call with SYS. Oh well, I will leave the C64 version to someone else. :-) The challenge is more about honor and glory and getting an excuse to show off old computers and/or skills with porting, but I do give out vinyl decals & stickers for prizes (http://imgur.com/a/iAS5T). I know that the TI-99/4A, Atari 400/800, Coleco Adam, MSX, and maybe some others also had sprites. Sprites aren?t really needed for porting to other systems, they?re just an easy way to move the player around the screen. The program could definitely be ported to systems that use simple character graphics or even plain text screens. The complete source code has been posted to github, and you can see the full rules and check out other submissions here: https://redd.it/3ko0nd -- Follow me on twitter: @FozzTexx Check out my blog: http://insentricity.com

8 years, 2 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, 2 months

assembler, disassembler for Intel 8089?

by spacewar＠gmail.com

Before I write my own, does anyone happen to have an assembler and/or a disassembler for the Intel 8089 I/O processor?

8 years, 2 months

ROM dumps of Intel MDS-2 IOC

by fulivi＠tiscali.it

Hi everyone, I'm looking for the images of ROMs installed on the IOC (I/O controller) board of Intel MDS-2 development systems. In particular I'm looking for the content of the character generator ROM (A19-2708) and of firmware ROMs (A50 to A53-4x2716). So far I had no success in googling them. My goal would be to contribute a good emulation of MDS systems to MESS, especially for what regards the look of the video terminal. Well, this is the plan, when "real-life" is not inteferring too much... Thanks a lot. -- F.Ulivi

8 years, 2 months

StorageTek 2920 9-track manual or instructions wanted

by axelsson＠acc.umu.se

Hi all, I have a Norsk Data ND110324 9-track drive which is a rebranded StorageTek 2920 with SCSI interface. So far I have only found a single manual for it, a quick guide card of 10 pages. Is there a manual out there which describes the unit a bit more in depth, like setting the SCSI address, diagnostic program codes, service, technical specifications and so on. So far I have got it to load a tape automatically and detect the recording density. Next step is to get it to talk to a linux-computer for imaging some old tapes. Thanks in advance, G?ran

8 years, 3 months

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test-drb July 2016