test-drb April 2012

test-drb@ccmp.vtda.org

195 participants
233 discussions

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, 4 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

7 years, 7 months

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

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

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

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, 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, 2 months

Stardent 19" workstation monitor

by vcf＠siconic.com

I have a monitor for a Stardent workstation. It's a re-badge Sony, model number 130-0001-01. Free for pickup, or 1.2 * cost of shipping to recoup time and trouble if you want it shipped. Please respond soon if you are interested as it will be going off for scrap in a week if there are no takers. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

9 years, 9 months

6809 SBC

by lynchaj＠yahoo.com

http://classiccmp.org/pipermail/cctalk/2010-January/282022.html It always suprised me that hre BBC micro used the 6502 rather than the 6809. By the time the Beeb was designed, Acorn had made a 6809 processor board for their System machines, so they must have had experience with the chip. THe Beeb is nice, but a Beeb with a 6809 processor would have been something else :-) -tony Hi! When I designed the N8VEM 6809 host processor it is loosely based on an article I read for the BBC computer called "Dragon in the tube". I am not very familiar with the UK microcomputers but apparently 6809 "coprocessors" were fairly common peripherals on their Z80 and 6502 designs. I used a similar concept for the N8VEM to allow its Z80 SBC to access the 6809 as a "host processor" peripheral on the ECB. One of the builders was able to get CUBIX running on the N8VEM 6809 host processor using the Z80 as its "IO processor". However, I can see how the implementation can get confusing because it is either a Z80 based system with a 6809 coprocessor or a 6809 based system with a Z80 IO processor. In reality it doesn't really matter but it's a matter of perspective. The N8VEM 6809 CUBIX implementation allows the use of ECB peripherals like IDE, video, floppy, serial, parallel, etc but it requires the Z80 to serve all the IO based on 6809 commands. I added the 6809 IO mezzanine board (power, ACIA, PTM, 2 VIAs, expansion bus) to give builders the option of using the 6809 host processor as a stand alone computer or to add separate IO to the N8VEM system when connected to the bus. The idea being to let the 6809 host processor interact with the outside world using its own IO and only involve the Z80 when absolutely necessary. The hardware seems to work OK but we'll see where the software goes. I think with CUBIX the 6809 N8VEM system becomes a lot more practical. The IO mezzanine fits on top of the 6809 host processor. You can see some photos here. These are out of date but give a good idea. Recently I fitted an improved serial cable and the nylon standoff hardware. Also the PTM seems to be working and that's good. http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder&param=m6809 I have many 6809 host processor and IO mezzanine PCBs so if anyone is interested please let me know. This would be a great opportunity for anyone who would like to do some 6809 hardware and software hacking. I think the N8VEM 6809 host processor is the only system I am aware of other than Dave's homebrew that is running CUBIX. There maybe some other homebrew systems out there too I can't find them after some searching. Thanks and have nice day! Andrew Lynch

10 years, 1 month

VT-180 (Robin) EPROM images?

by ajp166＠bellatlantic.net

> >Subject: VT-180 (Robin) EPROM images? > From: "Robert Armstrong" <bob at jfcl.com> > Date: Sat, 10 Mar 2007 20:23:04 -0800 > To: <cctech at classiccmp.org> > > Does anybody have images of the v2.1 Z-80 firmware for the VT-180 (aka >Robin) ? At least, I think 2.1 was the last version ever released. They >should be DEC part numbers 23-017E3-00 and 23-021E3-00. > >Thanks, >Bob Armstrong I have enough of them laying around I could supply the actual roms. I've never imaged them as It's easier to replace the code outright. Curious why are you looking for them? Allison

10 years, 5 months

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test-drb April 2012