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System Cards
Z80 CPU 8080 CPU 6500 Series 6800 CPU

I am no longer active in this hobby for the foreseeable future.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).

 

Z80 CPU
8080 CPU
6500 Series
6800 CPU

DG Systems
Bytemaster
System Cards
Keyboard
Printer A & B
Phideck
Disk Drives
Documentation
Software
Flyers
Magazine Ads

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

 

 
 

The Circuit Boards

A minimum Digital Group system consisted of a Processor card, an I/O card, and a TV Readout & Cassette card with a motherboard, and power supplies. DG owners could choose from a variety of other cards to complete their systems and perform many tasks. Pictured below are examples of many of the cards that were available from The Digital Group and are part of my collection. I also have several cards manufactured by other vendors both before and after the demise of Digital Group; AEON, TCS, Godbout, & etc. The TCS 32K Memory is the only after market item I am using in any system at the time of this writing, so it is the only one pictured below. This card is used in my Mini-Bytemaster along with the early 32K Static RAM card shown below.

I also have several boards that appear to have been "factory" assembled. The boards look to have been wave soldered--all via's are soldered through--and the solder job is consistent throughout the board. They also have inspection stamps on the front or back. Hmmm. 

Many of the boards shown below have been dusted off, but have not been restored in any way though several are in working condition; they were just the ones that were most accessible for picture taking. I also included multiple versions of the same boards, if I have them. Documentation is available for most of these boards by following the link on the left. I also have pages dedicated to each of the four processors available by clicking the links at the top of the page.
 

All photos below are approximately 1.7 Megabytes
 

2008-05-27a 052.jpg (1431950 bytes)
8K RAM Board

2008-05-27 146.jpg (1578243 bytes)
Early 32K Static RAM*

2008-05-27a 049.jpg (1655423 bytes)
32K Dynamic RAM (factory assembled)

2008-05-27a 055.jpg (1584682 bytes)
8K RAM Board

2008-05-27 150.jpg (1801585 bytes)
Early 32K Static RAM

2008-05-27a 050.jpg (1869918 bytes)
32K Dynamic RAM (factory assembled)

 

2008-05-27a 058.jpg (1628833 bytes)
Late 32K Static RAM

2008-05-27 142.jpg (1527485 bytes)
TCS Brand 32K Static RAM

2008-05-27 135.jpg (1480867 bytes)
Z80 Processor Board*

2008-05-27a 060.jpg (1794841 bytes)
Late 32K Static RAM

2008-05-27 144.jpg (1764180 bytes)
TCS Brand 32K Static RAM

2008-05-27 138.jpg (1560330 bytes)
Z80 Processor Board

 

2008-05-27a 068.jpg (1614924 bytes)
8080 Processor Board

2008-05-27a 116.jpg (1743140 bytes)
6800 Processor Board*

2008-05-27a 127.jpg (1714048 bytes)
6500 Series Processor Board*

2008-05-27a 070.jpg (1734815 bytes)
8080 Processor Board

2008-05-27a 117.jpg (1895378 bytes)
6800 Processor Board

2008-05-27a 122.jpg (1801360 bytes)
6500 Series Processor Board

 

2008-05-27a 062.jpg (1531509 bytes)
Video/Cassette, 32x16 Character--Rev A

2008-05-27 131.jpg (1401687 bytes)
Video/Cassette, 64x16 Character--Rev B*

2008-05-27a 098.jpg (1606277 bytes)
Bare Video/Cassette, 64x16 Character--Rev C

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Video/Cassette, 32x16 Character--Rev A

2008-05-27 133.jpg (1496965 bytes)
Video/Cassette, 64x16 Character--Rev B*

2008-05-27a 101.jpg (1662417 bytes)
Bare Video/Cassette, 64x16 Character--Rev C

 

2008-05-27 125.jpg (1239731 bytes)
Four Port I/O Board*

2008-05-27a 043.jpg (1370268 bytes)
Serial I/O Board

2008-05-27 121.jpg (1317876 bytes)
Floppy Controller--Single Density*

2008-05-27 128.jpg (1302570 bytes)
Four Port I/O Board

2008-05-27a 046.jpg (1396247 bytes)
Serial I/O Board

2008-05-27 124.jpg (1262812 bytes)
Floppy Controller--Single Density

 

2008-05-27a 078.jpg (1486134 bytes)
Floppy Controller--Double Density

2008-05-27a 082.jpg (1652121 bytes)
Phi-Deck Controller--Rev B

2008-05-27a 087.jpg (1625078 bytes)
Phi-Deck Controller--Rev C

2008-05-27a 080.jpg (1573370 bytes)
Floppy Controller--Double Density

2008-05-27a 086.jpg (1770698 bytes)
Phi-Deck Controller--Rev B

2008-05-27a 089.jpg (1654721 bytes)
Phi-Deck Controller--Rev C

 

2008-05-27 112.jpg (1309511 bytes)
Votrax Voice board*

2008-05-27a 074.jpg (1466697 bytes)
HAM Board

2008-05-27a 093.jpg (1520431 bytes)
I/O Prototyping Board

2008-05-27 115.jpg (1174078 bytes)
Votrax Voice board

2008-05-27a 076.jpg (1396322 bytes)
HAM Board

2008-05-27a 092.jpg (1555500 bytes)
I/O Prototyping Board

 

2008-05-27a 095.jpg (1661542 bytes)
Bare 8080 Processor Board

2008-05-27a 103.jpg (1790460 bytes)
Bare Z80 Processor Board

2008-05-27a 107.jpg (809477 bytes)
Bare Low Current Power Supply

2008-05-27a 097.jpg (1739587 bytes)
Bare 8080 Processor Board

2008-05-27a 105.jpg (1731785 bytes)
Bare Z80 Processor Board

2008-05-27a 106.jpg (951525 bytes)
Bare Low Current Power Supply

2008-05-27a 110.jpg (1287879 bytes)
Mini-Motherboard

2008-05-27a 111.jpg (1831285 bytes)
Standard Motherboard

* Denotes restored and working condition as shown.

 

 

256 Character Video Card 

This is Digital Groups original video card, the first product offered by the company. The memory chips are 1101 types (256x1 bits), and the layout is 8 lines by 32 characters. Kind of odd, but hey! It was VIDEO!  This card was designed for the Mark 8 Minicomputer, and was described in the "8008 packet #1", sold by the digital group starting in the fall of 1974. The packet consisted of software and hardware modifications and improvements to the Mark 8. When I got it, there were about a half dozen missing chips, I spent a bit of time reverse engineering it enough to identify and replace the missing parts before I received a copy of the 8008 packet.

The board has been assembled with a keyboard to form a TV Typewriter, and has a page on my web site.

 

mark8_dg_tvt_02.JPG (3177730 bytes)
First Digital Group Board, 8X32 Video

 


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