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My Collection
Mark-8 Minicomputer Apple-1 MOS Kim-1 V C F Imsai 8080 Kenbak-1 TV Typewriter LSI ADM-3A ASR-33 The Digital Group

I am no longer active in this hobby for the foreseeable future. 
I will no longer maintain or update the website, but I will leave it accessible to the web for as long as possible (years).


Mark-8 Minicomputer
MOS Kim-1
Imsai 8080
TV Typewriter
The Digital Group

My Collection
Test Equipment
Model Rocketry

Bryan's Old Computers


Select from the buttons above or click on any of the photos below to jump to the page for that item.


Mark-8 Minicomputer

The Mark-8 Minicomputer was the worlds first widely available personal computer. Introduced in the July 1974 issue of Radio Electronics. What made it even more personal is that you had to build it yourself!

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img_2407a.jpg (41968 bytes) The Digital Group

Among the earliest of all companies to offer a personal computer, the digital group began in August '74, initially  to support the Mark-8. They were among the first to offer users a "warm boot" from built-in ROM.

Digital Group TV Typewriter

After the introduction of the Mark-8, the digital group was formed to sell improvement information and add-on's to the Mark-8. This video card was their first product.

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asr-33_vcf.jpg (126736 bytes) Teletype Corporation ASR-33

The most common input/output device of the minicomputer and early microcomputer era was the ASR-33 Teletype. This version included a keyboard and papertape reader/punch. The machine communicated via serial interface at 110 baud, or ten characters per second.

MOS Technology Kim-1

MOS Technologies introduced the 6500 series microprocessors in early '75, and the Kim-1 as a demonstrator meant for engineering commercial product development. It turned out that the primary customers for this single board computer were hobbyist. 

The first batch of 6502 processors had flaws that made some functions unusable. Mine is one of these early versions. (Remember the early "math challenged" Pentium chips?)

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IMG_4409d.jpg (1099280 bytes) Apple Computer 

Apple-1 replica, and my own homebrew Apple-1, built in 1977 from plans drawn by Steve Wozniak. The Apple 1 is widely considered the most collectable of all old computers.

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My Kenbak-1 Replica Project

The Kenbak-1 was named the first PC by the computer history museum Apparently, they never heard of Simon. This my replica construction page.
(Tiny photo stolen from Erik Klein :)

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Imsai_8080.jpg (22786 bytes)  IMS Associates IMSAI 8080

The first "clone" computer. This was the industrial looking Altair clone with beefier power supply. A gift from Tom Apel, thanks Tom!!

The Vintage Computer Festival

The VCF takes place each year in Mountain View, CA, (near San Francisco) at the Computer History Museum. What fun!

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DSCF2914a.jpg (1468253 bytes) Lear Siegler ADM-3A

The next advancement in I/O after the teletype was the video terminal or  "silent teletype". The most popular of the early microprocessor era was the Lear Siegler ADM-3, and later the 3A, which was nearly a direct replacement for the ASR-33 Teletype (less tape punch/reader), but added many new features. It even offered lower case(!) characters as an option! Wow!


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Copyright 2008 Bryan's Old Computers
Last modified:
October 16, 2009