test-drb November 2010

test-drb@ccmp.vtda.org

162 participants
241 discussions

by fire＠dls.net

I know I posted this a few days ago, but I find it hard to believe that there are no Alpha Micro collectors on the list. Here is an opportunity to make some money by parting with your working Alpha Micro for no more than 60 days. Then you can have it back with ours (whatever you can salvage for parts, I think the MB is bad, but the rest works). Still no takers. I am told that AM6000, AM7000, AM8000 or Eagle 450 or Eagle 500 will work fine. Email me at fire at dls dot net. Bradley Slavik

13 years, 4 months

[TUHS] pdp11 question

by IanK＠vulcan.com

Oops, this was supposed to go to the whole list -- Ian > > > -----Original Message----- > > From: tuhs-bounces at minnie.tuhs.org [mailto:tuhs- > > bounces at minnie.tuhs.org] On Behalf Of Norman Wilson > > Sent: Thursday, November 18, 2010 10:58 AM > > To: tuhs at tuhs.org > > Subject: Re: [TUHS] pdp11 question > > > > Just to loop things around a bit: > > > > Some of the larger VAXes used small PDP-11s (and their > > bastard offspring) as console processors. > > > > This started with the very first VAX, the 11/780, which > > used an 11/23 as a console. The console ran a stripped-down > > system, possibly based on RT-11 or RSX-11, I forget (and > > am typing this on a train in the Outer Mongolia part of > > Texas where it's hard to look up references). > > > > It is an 11/03, according to the Console Interface Technical > Description manual and the part number of the processor board. The > system looks to me to be RT-11 based. I know that I could read/write > the floppies on an 11/03 running RT-11, which was how I recreated live > media from disk images. > > > I don't know the whole list of what was used as a console > > for different VAXes, but I do remember that the Nautilus > > series (8500-8550-8700-8800) used either a Pro/350 or a > > Pro/380, running P/OS, which was slightly more satisfactory > > than the rude English non-computer expansion of PoS might > > imply, but only slightly. Especially for those of us who > > wrote code to fit into UNIX on the VAX and talk to the > > console processor. > > > [snip] > > Another DEC machine to use an embedded computer as a console is the KL- > 10 processor. It uses an 11/40 running a modified version of RSX-11 > called RSX-20F. Given that the KL was introduced in 1975, it predates > the 11/780 in using this approach. -- Ian

13 years, 4 months

SCSI to MFM/RLL schematic

by afra＠aurigae.demon.co.uk

Hi, Does anyone happen to have the schematic of one of the SCSI->MFM/RLL boards ? I have the Adaptec ACB-4000 and Xebec S1410A board documents >from bitsavers but thy only have the schematics for the computer end. All the talk of interfacing to SCSI has got me wanting to have a go :) I'm just want to look and see how it was done in the olden days....failing that I guess I'm gonna have to start tracing tracks..... Cheers. Phill. -- Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric ! "You can twist perceptions, but reality won't budge" -- Rush.

13 years, 4 months

Drives which used an MC3470A head-amp

by classiccmp＠philpem.me.uk

Hi guys, As you might have gathered from my other thread, I'm toying with the idea of building a replacement controller card for my two dead double-sided Amstrad disc drives. Ideally I'd like to use as many "standard" parts as possible to ease debugging and future repair. I'll probably use a GAL to handle head-stepping and the write protect lockout, and LSTTL for the bus interface. I'm also planning on adding an overvoltage crowbar (or maybe some form of a MOSFET OVP switch) on the 5V rail to protect against the common killer of these drives: plugging them into a PC PSU (the power plug is a Berg floppy power connector, but with a mirrored pinout). I've got my hands on a couple of Texas Instruments MC3470A floppy disc read amplifier ICs, and the Apple Disk II schematics suggest how this can be tied to a drive mechanism. What I'd like to do is look at a few other drives which use this chip to make sure I understand everything correctly (a double-sided drive with a single 3470A would be handy). If I'm being honest, the TI datasheet for the chip is utter crap... So does anyone know of any other FDDs -- besides the Disk II -- which used the MC3470A as the head amplifier, or maybe a few applicable application notes? Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

13 years, 4 months

First binary encoding of the alphabet?

by cclist＠sydex.com

I've been reading William Blair's 1807 article on cryptography, called "Ciper": http://www.jdege.us/crypto/blair-cipher.pdf Around PDF page 16, near the bottom of the first column, he proposes a code that represents letters of the alphabet, using the symbols a and b. What's interesting is that this is nothing more than a binary code, with A being aaaaa, H being aabbb and so on to Z being babbb. Is this the first mention of using a binary code to represent letters of the (Roman) alphabet? For the time, a remarkable document. --Chuck

13 years, 4 months

VAX 11/750 and Pyramid Technologies machine available in Brisbane, Australia

by sellam＠vintagetech.com

Hello All! See below. Please respond to original sender. Reply-to: <zzpeter at inbox.com> ---------- Forwarded message ---------- Date: Mon, 29 Nov 2010 05:20:22 -0800 From: peter ... <zzpeter at inbox.com> To: donate at vintage.org Subject: Re: old computers available Hi, I have a pyramid technologies computer, and also a Vax 11/750 (with many manuals, spare circuit boards, cables , monitors, tapes and misc parts)... which sadly I am unable to keep in storage any longer. Hence I am looking for a person or organisation to donate them to... The catch... I am in Brisbane (Australia), do you have a branch in Australia, or know of any group, or person in Australia that would be interested in taking care of these machines? Regards, Peter --- EOM -- 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 ]

13 years, 4 months

SCSI to IDE

by jlobocki＠gmail.com

Ok, so I have been doing research, and this affects everyone here who collects SGI, apple, and anything using scsi. in the near future, the supply of smaller SCSI drives will eventually dry up, due to failure from age and lack of supply, as I believe they are no longer manufactured, unless for the industrial/server market. I could be wrong on that part, but I take it as such because my searching for them brings up nothing new. what does that mean for collectors? it means that your neat little apple or SGI or etc will run, until the scsi disk dies, then we will be left cannibalizing machines for disks, paying ridiculous prices for leftover scsi disks, which will skyrocket because of the small supply. So what is our option? I have seen SCSI to IDE adapters around, but they go up into the $100's to $200's, say you have a minimum 10 machines, that leaves you somewhere between $1,000 and $2,000 total, before the disk or devices. If we could design a simple SCSI to IDE interface, we could be set for a good long while on storage for these devices for a decent amount of time. There are all sorts of adapters to IDE, there is CF to IDE, SD to IDE, SD to CF which could be placed in a CF to IDE adapter if need be, i'm sure one could also rig up a USB drive to SCSI if one tried, but I could be wrong. Having said that, I know nothing about programming microcontrollers or simple processors, but I have seen people on the board who do. I'm sure if we can find a chip capable, and lay out a schematic, source code, and possibly a board layout, members could source their own boards and components to build their own devices at home (given they have a chip programmer), so no one person has to take on the responsibility of supplying parts, kits, finished devices unless they so choose to. This is just an idea, if nothing becomes of it, no big deal, just putting it out there.... -Joe

13 years, 4 months

Deleted partition recovery

by Hollandia＠ccountry.net

A primary partition on C drive of one of my computers is gone. FDISK says that there is no partition on that drive. Is there any way to undo this without losing the information on that drive? I will of course need to do this from DOS...

13 years, 4 months

Sac State 8008 dumps online...comments welcome!

by bdamer＠digitalspace.com

CC-folks, What may be the earliest substantial surviving intel 8008 code (circa 1972) has been rescued from eight 1702 PROMs (thanks Dwight Elvey) and disassembled (thanks James Markevitch) and is now online for comment at: http://www.digibarn.com/stories/bill-pentz-story/8008-listing.html The team working on this is making their best guess that this was the particular code that controlled the Tektronix 4023 color raster display which in turn had boards in a card cage that controlled the other peripherals. Original SacState project initiator and leader Bill Pentz donated the surviving version of this system (consisting of boards and some documentation) a couple of years ago. One board contained the 1702s and we had no idea if there was anything still left in them. Surprise surprise there was! The full system and its story is described at: http://www.digibarn.com/stories/bill-pentz-story/index.html with a 3D graphical reconstruction of what it might have looked like (it drove a Diablo hard disk pack, ASR-33, serial interface, keyboard, Tek 4023). The history, the claims... So far with many folks weighing in, this might indeed be the "first" complete microcomputer system, with peripherals, a primitive OS, language and etc. It was built by Cal State Sacramento working with Tektronix and Intel, starting in the spring of '72 and getting stuff operational over the summer and fall of that year. As best as project leader Bill Pentz can recollect this system was processing 50,000 patient medical records and plotting color charts on the Tek by spring of '73. It also ran IBM BAL (370 mainframe assembly language programs) in emulation. We are still looking for someone who can peruse their backs issues of Popular Electronics from '73 and '74 to look for a brief mention of this project (anyone got a set?). So feel free to comment on the code. Note that for one eROMs there was either a bent pin or bad line -> bit 5 missing so its guesswork there. bruce

13 years, 4 months

IBM transistors and SMS cards

by wdonzelli＠gmail.com

I was cleaning up the estate of an MIT prof, and came across some Philco transistors with odd markings that I suspect were made for IBM. Generally, TI made the transistors for IBM, but I have seen a few SMS cards with Philcos on them. Philco transistors look a bit like bullets - about 1/2 inch long, and maybe 3/16 inch diameter, metal with a rounded top. Often the leads are insulated, as the spacing is very tight. I do not have any SMS cards with Philco transistors. Does anyone (CHM 1401 crowd?) have any they could inspect for me? I would like to know the numbers printed on the case. -- Will

13 years, 4 months

← Newer
1
2
3
4
5
6
7
8
9
...
25
Older →

Jump to page:

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 November 2010