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TRS 80 Model 4P 26-1080 and 26-1080A

by billdeg
Total messages in this thread: 4
Updated: [ 26-1080 S/N 002615 ] 11/28/2010
4 TRS 80 Model 4P computers.
Two of these are 26-1080's and Two are 26-1080A's. The green screen displays are 1080A's. Although some 1080's are non-gate array units, the 1080A's are probably all gate array.
To run the diagnostic package in the ROM, hold down the period key ( . ) and then power on the system. You'll access a ROM program for testing the system. It looks like RAM tests.
Here is a picture of the two types of cover latches one can find on the 4P to clamp the cover to the chassis. I prefer the metal.
Notes from 4p Technical Reference Manual http://www.classiccmp.org/dunfield/trs80/">... [ read more ]

RAMCheck Innovations 64-256 K RAM Tester

by billdeg
Total messages in this thread: 1
RAMCheck Innovations 64-256 K RAM Tester. This device works tests for shorts. Also id's whether chip is a RAM chip at all, and if so whether it's a 64 or 256K chip.
">... [ read more ]

TRS 80 Color Computer 2

by billdeg
Total messages in this thread: 2
Updated: [ Tandy Color Computer 2 (Gen II) ] 02/26/2013
The TRS 80 Color Computer 2 model 26-3027.
Boot screen and PRINTMEM. As you can see by the lower than expected memory (this is supposed to be a 16K machine), one of the 8040517 RAM chips is bad. The 16K Coco II did not use "regular" RAM like the more expensive Coco II.
Coco 2 pics (multiple models)">... [ read more ]

Tandy TRS 80 Color Computer 26-3002A

by billdeg
Total messages in this thread: 1
The TRS 80 Color Computer 1 model 26-3002A. This unit is pretty beat up looking, but it works.
Boot screen and PRINTMEM of the coco 1
more pics">... [ read more ]

Tandy / Texas Peripharals 5 1/4" drives

by billdeg
Total messages in this thread: 1
Three 5 1/4" disk drives commonly used with Tandy computers from the TRS 80 model 1 with expansion unit and the Coco 1 and 2.
I have begin diagnostics and repair of a set of about 10 external drives. Mostly these enclosures have the Texas Peripherals International (TPI) model 10-5355-00 installed.">... [ read more ]

Commodore BX-256-80 - 8088 Co-processor

by billdeg
Total messages in this thread: 4
Updated: [ 256-80 ROMs are fine with 8088 ] 11/19/2010
The other day I saw some rare Commodore CBM 256-80 computers for sale and despite the lack of keyboards I bought them. Turned out to be a great deal!
CBM 256-80 with 8088 co-processor
Upon inspection of the insides, I was surprised to find that both were actually the BX models. This is truly a rare find, indeed. The 256-80 BX is also known as the CBMX256-80 and the BX256-80. In the US the CBM 256 "BX" model with the 8088 co-processor was not officially sold by Commodore. The few 8088 cards that were produced in test/prototype batches were given to the Chicago B Series User Group for free. I have a copy of the release letter to prove it. Bruce Faierson, the 2nd president of CBUG and owner of Northwest Music near Chicago, installed a few CBM 256-80's with these prototype">... [ read more ]

Litton Sweda International 8452

by billdeg
Total messages in this thread: 1
A computer appeared on the floor of my shop the other day. It's a Litton Sweda International Floppy Disk Model 8452. I am not sure if this is a single 8" floppy disk drive or a computer with a floppy disk drive. On the back is a 15 pin female connector and two sets of four circular female 8-pin connectors. More to come.">... [ read more ]

Tandon 100 1a/2a shugart 450 mpi 52

by billdeg
Total messages in this thread: 1
Today finally started working on the 30 full-height 5 1/4 drives that have accumulated over the past few years...">... [ read more ]

Bryans Analog Plotter Model 20170/S

by billdeg
Total messages in this thread: 1
Bryans Analog Plotter Model 20170/S Bryans is an English company that made analog plotters. Click image for picture.
more photos">... [ read more ]

Atari 520ST

by billdeg
Total messages in this thread: 4
Updated: [ Atari 520ST SF354 Replacement ] 11/03/2010
The 1985 Atari 520ST Computer
This is a 16-bit Atari computer system with a 68000 processor. The 520ST was marketed to compete with the early Amiga computers and has similar capabilities and interface. The 520ST usually came with an SC1224 monitor and an SF354 disk drive. This particular system's SF354 disk drive is not working. More to follow. Pictures">... [ read more ]

Toshiba T1000 laptop

by billdeg
Total messages in this thread: 1
The 1987 Toshiba T1000 laptop. This is not the first Toshiba laptop, the T1100 came first.
More Pictures">... [ read more ]

Mark 8 Microcomputer Video

by billdeg
Total messages in this thread: 1
Mark 8 Microcomputer Jon Titus LCF Group Collection Floyd Virginia http://www.youtube.com/watch?v=RcgeWmh8ym8">... [ read more ]

Ed Roberts (MITS / Atlair) dies at 68

PDP 11 Unibus Machine Controller

by billdeg
Total messages in this thread: 1
What we have here is a PDP-11 class Unibus machine controller. From the front panel it looks like this computer was used to splice "something". This is not the complete system. Click image for larger view.
Digital M series flip chips populate a backplane unit. Here is a close up view of the card labels. Click image for larger view.
I have the Digital book that describes the function of each flip chip in detail. There is no CPU logic, this unit was probably a custom analog">... [ read more ]

IBM Thinkpad 500 model 2603

by billdeg
Total messages in this thread: 1
The IBM Thinkpad 500 model 2603 was an early netbook sized laptop from late 1993. This system boots up to Windows 95, but it originally came with Windows 3.1(1).
more pics ">... [ read more ]
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