test-drb

test-drb@ccmp.vtda.org

101090 discussions

by pete＠pski.net

I?ve recently acquired a rare complete set of 10 TRS-XENIX 1.0 Development System floppy disks. I?ve done quite a bit of 8? disk imaging so I'm fairly comfortable using ImageDisk, cleaning disk heads, etc. I?ve run into a scenario with these disks that I have not had to deal with before. Since this is the only complete set of this software I?ve ever seen, I need to be really careful with how I proceed. The media itself looks pretty good. No scratches, no blotches. However, on a number of disks the sleeves have warped. I am afraid that this will damage the media when I spin them up. I?m thinking of cutting open the sleeves and placing the media in new 8? floppy sleeves. I?ve also heard about baking the media, although I?ve never tried this and not sure of its value. What are your thoughts on how to proceed?

9 years, 3 months

DEC DSSI troubleshooting (RF71)

by witchy＠binarydinosaurs.co.uk

Hi folks, I've got my VAX3800 resuscitated after many years in limbo and two of the four RF71s in there have gone bad. Has anyone tried swapping the controller boards between drives? Is it just a matter of letting the drive auto-calibrate or do I need to SET HOST onto the controller and tell it it's on a different HDA... Here it is in a happier mood shortly after first powerup: http://www.binarydinosaurs.co.uk/VAX3800.jpg (not my best LK201 keyboard but it was the closest :) ) -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

9 years, 3 months

HP-1000 12044A 12825A HDLC Interface manuals available anywhere?

by glen.slick＠gmail.com

I don't see these manuals online at either bitsavers.org or hpmuseum.net. Does anyone have copies of them available? 12044-90001 HDLC Direct Connect Interface Hardware Reference Manual (12044A for A/L-Series) 12825-90001 HDLC Direct Connect Interface Hardware Reference Manual (12825A for M/E/F-Series) I have more than one HP-1000 CPU. Just curious what it would take to connect some of them together running 91750A DS/1000-IV software.

9 years, 3 months

Booting PDP-11's from RX02's

by jnc＠mercury.lcs.mit.edu

So, I'm winding up to boot Unix V6 from an RX02 floppy. So I need two things: - Details of how DEC ROM bootstraps boot from RX02's. I vaguely recall seeing documentation of this somewhere (e.g. which sectors it loads, etc), but now I can't find it. Don North has dumps of the RX02 ROM's, but I'm too lazy to read through the code and figure out how they work. Is there some documentation which covers it? I did a quick Google search, but if there is anything out there, my Google-fu was inadequate. - Did anyone ever do an RX02 driver for the V6 disk bootstrap? (Well, I guess a V7 driver would work, too.) Note: what I need is _not_ either i) the Unix OS driver for the RX02 (I found one of those already), or ii) a driver for the v7 standalone second-stage bootstrap (which would probably be in C). The thing I'm looking for would be called rx.s, or something like that. Yes, I could write it, but again, I'm lazy! :-) Noel

9 years, 3 months

Compupro Disk Images Uploaded

by billdegnan＠gmail.com

I have uploaded a set of disk images from My Compupro system with an 8085 and 8086 card, plus regular z80. The thread starts a number of years ago, but today I just updated, at the bottom, to include images of the disks I have for the system. Some interesting concurrent CPM and DOS stuff, not sure if this is really MS DOS 1.25 or not, never got it to work on my system. I'd love to see someone else make it work. Thread: http://vintagecomputer.net/browse_thread.cfm?id=265 Just get the IMD images: http://vintagecomputer.net/disk_images/COMPUPRO/ As always, thanks Dave Dunfield, please use the images with the proper licenses, etc. Bill

9 years, 3 months

SEEKING GOOD ILLUSTRATIVE MATERIAL ON IBM ADD ON BOXES GOT A STACK..

by COURYHOUSE＠aol.com

SEEKING GOOD ILLUSTRATIVE MATERIAL ON IBM ADD ON BOXES GOT A STACK.. So need hi res scans of catalogs brochures etc showing them all stacked and what when with what. We had an early IBM pc for a while....but never this many add on boxes! I am lost... Remember back in the 80s I sold HP stuff... any help and guidance appreciated to make this all come together into something nice visually! thanks Ed Sharpe archivist for SMECC couryhouse at aol.com

9 years, 3 months

DEC bus transceivers

by jnc＠mercury.lcs.mit.edu

Re: DEC bus transceivers > From: allison > Actually since about 1987 I've used about 1200 pieces of the 8641 alone > repairing boards at the commercial level. Well, that's over almost 30 years - and your total from that period is about 4% of the remaining stock (and in a commercial operation, to boot, not hobbyist)... > If you going to build a board or three maybe even 20 its not a big deal > but its not a reliable source of predictable quality. Sure, but try looking at it from our perspective: we either use an out-of-production part, or have to design something (almost certainly from discretes) that meets those specs; and we actually looked at the latter (viz. Dave B's design). However, after some pondering, and taking everything (including all the below) into account, we decided to go with the original chips, since they were still sorta available. Which is why both we and Guy have stocked up on them, at the start of the process: we don't want to crank out boards designed for a certain part, and then not be able to get the out-of-production parts the boards were designed to use. If we were designing something for serious production, that wouldn't be an option, but for limited-volume hobbyist use, it is. The choice of an out-of-production part does have a down-side, but it's minor (and mostly alleviated by the pre-buying), and the other options were (in overall sum) worse. > If you get to the bridge your talking redesign in reality or an > expensive buy from unreliable source then testing them in bulk. But, but... I'm _already_ buying them from unreliable sources, then testing them! :-) But to be serious - if the demand for QSIC's, etc, runs the well of DS8641's dry, yes, we'll probably have to re-design. In other words, we'd be right where we'd be today if we decided not to use out-out-production parts. Noel

9 years, 3 months

ContrAlto V1.1 Released

by JoshD＠livingcomputers.org

Hi all -- Just wanted to let you guys know that a new version of the Xerox Alto emulator I've been working on at the LCM+L has been released; V1.1 of ContrAlto can be downloaded from: http://www.livingcomputers.org/Join/Online-Systems.aspx. At this point, the vast majority of software appears to be working properly, if you do run into any issues please let me know! ContrAlto is open source, so if you want to hack on it the source is available on our GitHub site at https://github.com/livingcomputermuseum/ContrAlto. Thanks! - Josh

9 years, 3 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

9 years, 3 months

CMI expandacore18

by tedknowlegy＠gmail.com

I too have been searching for documentation/schematics for the Cambridge Memories, Inc. Expandacore18 4k core memory boards. I have an old Diversified Numeric Applications Med PL/185 machine which is a clone of the Raytheon 703. This machine has 16k of core with 4 of these boards. -- THE BLUES IS THE TRUTH. IF IT'S NOT THE TRUTH, IT'S NOT THE BLUES. (Willie Dixon)

9 years, 3 months

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb