test-drb

test-drb@ccmp.vtda.org

101090 discussions

by ddameron＠earthlink.net

Hi Doug and all, At 05:19 PM 7/17/98 -0500, you wrote: >> 5) Check the +8, +/-16, and GND pins on the bus connectors before >> powering up, make sure nothing's shorted. > >I found the power supply wasn't very well regulated, so you might see >higher voltages without a load. Which pins on the S-100 bus correspond to >those volatages? I just checked the mobo terminals, one of which was >unlabeled. Pins 1-50 on front, 51-100 on rear. Pin 1, 51 +8 Volts. Leftmost from the front, front and back. Unregulated (just filtered rectified DC from the power transformer) for the +5 volt regulators. (Usually very easy to trace or test) Pin 2, +16 Volts, unregulated. Pin 52, -16 Volts, unregulated. In my system I put fuses in these lines. Make sure the filter capacitors have bleeder resistors attached, so they will discharge without a load. Otherwise you might have problems when plugging in a card later :-(. Pin 50, 100 Ground. There were other ground lines on later cards, which you may have to check for when you start to mix cards, such as pins 20, 70, which were Unprotect, Protect in the early S-100 systems. -Dave

28 years, 1 month

Q-bus boards I need ID of...

by cfandt＠servtech.com

There are actually three boards I need to ID, the third is possibly a tape controller. Here's the rundown: #1 A Q-bus dual width board made by DTC. Has a 50-pin header next to a single ejector handle. All TTL chips, no LSI or CMOS devices. Two 8-section DIP switches on board. Only markings are a FAB, ASSY, REV and S/N numbers. The ASSY number is 007-00002. Could this be a Q-bus SCSI board (I hope, I hope, I hope)? But there's no CPU or ASIC, etc. onboard to handle DMA, SCSI device protocoll, etc. :( An appropriate driver in conjunction with the OS would have to do this. #2 A Q-bus quad width board of unknown manufacture. Two 50-pin headers at handle-edge of board. A marking on the component side says it's a "Q BUS/LEXID INT." with a number 77D609871P1 under it. A number stamped on the backside is "GE77D609871G1" with "SER NO- 44" under it. Those part numbers look like old GE part numbers. Did General Electric make any equipment for the DEC world? #3 This is what I feel is an Archive tape controller. It has "ARCHIVE CORP. Copyright 1983" silk screened onto the component side. No other numbers on the silk screen, dang it. It is 5.5" x 7.75" with a 50-pin edge connector (marked "J1") on one 5.5" end and a 50-pin header (marked "J3") at the other end. "J2" is a 4-pin recepticle which is the same as the power connector on a 5.25" floppy or hard drive and is on the edge connector-end of the board. The EPROM label has 80182-010 on it. Has an 8031 microcontroller chip, an 8155 and an Archive LCC ASIC plus a bunch of TTL and one small CMOS RAM chip (Mitsubishi M5M2167P-70). Other numbers found on the board seem to be component part numbers however there is a hand-written number on the solder side which is 80158-013/A. Could this be an important identifying number? I want to try to identify these boards to see if theyt are useable in the systems I'm keeping, especially item #1. Thanks for the help. --Chris -- -- Christian Fandt, Electronic/Electrical Historian Jamestown, NY USA Member of Antique Wireless Association URL: http://www.ggw.org/freenet/a/awa/

28 years, 1 month

DIGI-COMP 1 Assembly Instructions now available

by tomsaddressformaillists＠altavista.net

Due to popular demand, I have finally gotten around to adding the DIGI-COMP 1 Assembly Instructions to the collection of other scanned DIGI-COMP 1 manual pages at http://galena.tjs.org/digicomp/ . They are all 300 DPI grayscale images - in other words, huge! The parts list alone (Page 1) should be immensely helpful for those wishing to create their own DIGI-COMP. Thanks to everyone who e-mailed me over the past few days! Tom -- This account is used so mailing lists don't clutter up Tom's real account. If you really want to talk to Tom, use tom(at)galena.tjs.org

28 years, 1 month

sources

by icyblackhand＠hotmail.com

I live in Union County NJ. Are there any good old computer sources around here??? Mike ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

28 years, 1 month

Rebuilding Mac Portable batteries

by rcini＠email.msn.com

After a little research, I figured out how to rebuild a MacPortable battery pack for about 1/3 the cost of buying one on the resale market (I've seen prices between $60 and $75 per battery). Anyway, the pack is rated at 6v/5ah, and contains three, 2v/5ah Gates Cyclon "X" cells. The X cells are two sizes above the conventional D battery. Gates no longer makes these batteries, having gotten out of the battery business. Hawker Energy Products (http://www.hepi.com) now makes these cells. These are available from Battery Specialties (1-800-854-5759) for $7.24 each ($21.72 total). Opening the battery case is also easy. The pack top is ultrasonically welded to the bottom case, but if you score the top plastic in the groove where it meets the bottom case, and then bang it with a small slot-headed screwdriver and a hammer, you can open it easily. Replace the internal cells with the new ones, observing all polarity markings and ensuring that all insulating plastic and foam pieces are replaced. You can then seal it with plastic welding cement such as X7. The only problem that I can see is creating the bars that join the cells. I'll probably use 12g copper wire in stead of bus bars. Now all I need is the batteries... Rich Cini/WUGNET <nospam_rcini(a)msn.com> - ClubWin! Charter Member - MCP Windows 95/Windows Networking - Preserver of "classic" computers <<<< ========== reply separator ========== >>>>>

28 years, 1 month

VC404 The Standard

by lwalker＠mail.interlog.com

One of my recent curbside finds is a machine put out by a Canadian company based in Waterloo Ont called Volker-Craig model vg-400. On the front it has a title VC404 The Standard. It has a k-b attached with ribbon cable which is about the size of a C64 with Function Pf1-12 buttons as well as a separate pod with APL,PAGE,FULL,LOCAL on the left vertically. There is a full qwerty alphabet and numerical pad as well as some specialized keys the most unusual of which is a key labelled "rub-out" and no down arrow. In the back it has a 25 pin RS232 connector, a BNC labelled "composite video" ,2 switches : one 3-pos.to configure parity the other "Transparent on off" It also has cutouts for parallell and serial (maybe a 9pin dshell for different modems) I haven't opened it up yet, and I must admit to doing what the impeccable Tony Duell would deem unforgiveable (sorry Tony, Couldn't he'p m'se'f) I plugged it in and tuned it on. It worked except for a stuck k-b which stopped printing to screen when I punched another key than local on the right-most pad. Obviosly a terminal of some sort, but the keypads are not what I would expect. My guess is it's a terminal for the deaf which hooked up to a service. But why all the other k-b functions. Any ideas ? ciao larry lwalker(a)interlog.com

28 years, 1 month

Thanks to the list...

by Anthony.Dellett＠Staples.com

Well... I finally found one, I ordered a used Imsai 8080 from an undisclosed place in CA (they had one on consignment) and they're shipping it to me here in Boston. Thanks to those on the list who gave me pointers on how to find one. Now I gotta order replacement switches for the front panel (Tony heads to his web browser) Tony

28 years, 1 month

Thanks to the list...

by allisonp＠world.std.com

< 2) DISCONNECT THE FRONT PANEL AC SWITCH!!! Put an on/off power switch < in the back, use a hole next to the fan (most back plates had one. < Don't run the AC power through the front panel. This one applies to Altair8800s BIGTIME and any others that has mains ac near logic. The designers that did that should be made to stand in a puddle and work on it! Allison

28 years, 1 month

Thanks to the list...

by peacock＠simconv.com

Not so easy, you would have to grind down the back spacers so the front panel stayed in alignment with the bus slot. Just adding the ring would push the panel card forward. Jack >Don't know how they are but I can guess - has anyone tried puuting the screws in, then the spacers, then putting a C or E ring on the screw as a keeper to make it a captive screw and spacer?

28 years, 1 month

Thanks to the list...

by peacock＠simconv.com

> Well... I finally found one, I ordered a used Imsai 8080 from an > undisclosed place in CA (they had one on consignment) and they're > shipping it to me here in Boston. Advice to a new IMSAI owner: 1) if you take the front panel off, tape the plastic sandwich with the film for the front panel logo so it doesn't come apart. Also, tape the allen head screws on so they don't come out. This is real handy when the time comes to reassemble. You will discover you need 4 hands to do it: one to hold panel, one to position screws, one to hold spacers in back, one to tighten screws. 2) DISCONNECT THE FRONT PANEL AC SWITCH!!! Put an on/off power switch in the back, use a hole next to the fan (most back plates had one. Don't run the AC power through the front panel. 3) If its been heavily used, chances are the bus connectors may be worn. Wiggle cards a bit when STOPed and see if status lights change. You might have to hunt for the least worn slots. 4) Look for purple plague. If it's old, the socketed IC pins or card edge connectors may have oxidation (usually purple or black discoloration). You may need to check the front panel for this if it's socketed. 5) Check the +8, +/-16, and GND pins on the bus connectors before powering up, make sure nothing's shorted. Jack Peacock Using IMSAIs since 1975

28 years, 1 month

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