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IBM General Purpose Bus Adapter

by billdeg
Total messages in this thread: 1
I have a new project planned, to experiment with an IBM XT, a Micro Computer Systems IEEE hard drive, and an IBM General Purpose Bus Adapter and software. The parts were borrowed from the University of Delaware Computer History Museum Project. For now pics of IEEE kit for IBM PC">... [ read more ]

S-100 RAM Cards

by billdeg
Total messages in this thread: 2
Updated: [ 32K Continuous RAM ] 01/25/2008
I have gotten more confident with my ability to conclusively test various s-100 RAM cards, allocate programs to specific locations, change memory values, etc using my IMSAI. I can also assign the memory pages (0000-1000, 1000-2000, etc.) so that there can be more than one RAM card installed without conflict. I have installed 32K into the IMSAI. As I identify good RAM cards, I can put some into the SOL-20 I also have on the table. I have a small pile or RAM cards that I have accumulated from various places. I also soldered up a cassette cable for the IMSAI. I broke down and bought a new Radio Shack tape recorder so that I can count on a reliable drive when testing cassettes on an S-100 system. I have some Altair BASIC tapes that I want to load. After that I plan to attempt a Micropolis controller card and 2 or 3 compatible disk drive. The Micropolis cards">... [ read more ]

1973 Tech Pictures

by billdeg
Total messages in this thread: 1
------------------------------ Message: 10 Date: Fri, 25 Jan 2008 16:15:30 +0100 From: "pichotjm" Subject: I propose to make the journey in 1973... To: Message-ID: <003901c85f65$1fd07570$2601a8c0@JM3800> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original I had the opportunity to conduct a series of photographs when I participated in the fair 'Le Bourget' in 1973. You will see about 200 original pictures of displays, keyboards, computer terminals, cameras, radar displays, screen shots of weather, tactical, electric power plant, road traffic, and 8 american or soviet satellites. The visit is here: http://pichotjm.free.fr/.../Techno73US.html The root address http://pichotjm.free.fr will lead you in early computers... (1954 to 1975) Enjoy! JMP ">... [ read more ]

Byte BYT-8 S-100 Computer

by billdeg
Total messages in this thread: 1
Pictures of my Byte BYT-8">... [ read more ]

Exatron Stringy Floppy Update

by billdeg
Total messages in this thread: 3
Updated: [ Belt Replacement Exatron Stringy Floppy ] 01/23/2008
I have found a vendor for drive belts, and I have mailed out a snapped belt for analysis. The company is called Pyramid. I will post an update when available. I have four drives that need belts, and about 100 stringy floppies to read.">... [ read more ]

64 and 256K DRAM Testing Service

by billdeg
Total messages in this thread: 1
I have a RAMCHECK brand 64Kb / 256Kb DRAM chip tester...if anyone needs a chip tested, let me know. You send me the chips and I return then in whatever you sent them. The price/trade is negotiable. Limited time offer. Contact me if interested. 16 pins - here are some examples: 64K: 4164 8164 4164C 3764 4264 4164 4864 256K: 4256 81256 6256 41256 1256 0256 4257 (nibble mode) 81257 41257 50257 ">... [ read more ]

TM990/101 M

by billdeg
Total messages in this thread: 5
Updated: [ FAO Richard Lynch (was TM990/101 M) ] 01/19/2008
I have a TI chassis I have been unable to locate documentation. Can anyone help shed some light on the following. .? The card chassis: Within a Steel 4-slot Texas Instruments card chassis the size of a shoe box are four Texas Instruments cards manufactured in the US. These cards resemble a regular s-100 card but the 100 contacts are off center, to the left when viewing the component side with the 100 pin side down. Printed on the chassis is Assy No. is 0994676-0001 and Diag No. 0394677. I do not have a power supply, but I assume you'd attach to terminals on the back of the chassis somehow (?). Inside are 4 cards. Two cards are similar are RAM/EPROM cards with 32K in each (8 x 4 rows I assume = 32K?). The RAM is a mix of TMS 4045-30NL, TMS 4045-30, and TMS 4014NL. There are no Eproms installed, but there are two rows of empty slots on the card. Each card has 8 dip switches. ">... [ read more ]

Replacing an Apple III Power Supply

by billdeg
Total messages in this thread: 2
Updated: [ Replaced Power Supply ] 01/08/2008
Received an Apple III not powering up. Noticed that the fuse appeared to be blown. It's a 5mf 2 3/4 A fuse about 3/4" tall. Confirmed that this the correct fuse. Bought replacement fuse, that one popped too...must be a bad power supply...">... [ read more ]

IBM PS/2 model 70

by billdeg
Total messages in this thread: 2
Updated: [ Source for PS/2 1.44 Drive 15F7503 ] 01/06/2008
I picked up an IBM PS/2 model 70 but it has a bad (or dirty) disk drive - working to restore to Windows 386 (thanks Bryan) and DOS 4.0, as it would have had in the Summer/Fall of 1988 when the 70 was launched. My 70 has 6 Megs. No, I am not loading OS/2.">... [ read more ]

IBM Thinkpad 755 CD

by billdeg
Total messages in this thread: 1
I have an IBM Thinkpad with a bad keyboard, I plan to replace and rebuild. more to follow. ">... [ read more ]

Data Acquisition Corporation DAC-512

by billdeg
Total messages in this thread: 1
FYI The following link was submitted through this web site of a Data Acquisition Corporation DAC-512 brochure scan by Charles Falconer: http://cbfalc...t.net/firstpc/ Chuck designed the machine. He was VP and Chief Engineer Please use the address below for any replies. Chuck F (cbfalconer at maineline dot net) http://cbfalconer.home.att.net">... [ read more ]

Research Library

by billdeg
Total messages in this thread: 1
One of these days I will post a complete list of all of the books and magazines, product literature and docs on hand. Here are a few snapshots: Pics">... [ read more ]

Toshiba Laptops

by billdeg
Total messages in this thread: 1
I have a couple of Toshiba Laptops that do not work. I believe that they're salvageable, but I am not that interested in them. Contact me if you want them cheap. Pics ">... [ read more ]

Commodore troubleshooting links

by billdeg
Total messages in this thread: 1
Here are some useful Commodore troubleshooting links. http://www.zimmers.net/a...rs/Commodore/index.html">... [ read more ]

Byte June 1980 I-O Expansion TRS 80

by billdeg
Total messages in this thread: 2
Updated: [ Byte June 1980 I-O Expansion TRS 80 ] 11/16/2007
I received this request: "..Hello, Years back i built for my model 1 an RS232 port based on an article in Byte (June 1980). I made some changes to the design which i have noted down. However i lost the original article (rather thrown away years ago all my copies of Byte...). Can somebody get me a scan of this article (around page 50) or direct me to a place i can find it on the internet (Byte.com does not carry it)? Hope somebody can help me as i am trying to fire up my model 1 again. .." Here is the article: Byte June 1980 I/O Expansion TRS 80 Byte June 1980 Cover ">... [ read more ]
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