The 6809 CPU Board

Acorn System 6809 CPU Board Image

"This Eurocard (100 x 160mm) is a plug-in replacement for the 6502 CPU card to upgrade systems to use the advanced facilities of Motorola's 6809 8-bit processor.

This microprocessor is generally considered to be the programmer's processor and is ideally suited to run high level languages such as Pascal. The Acorn 6809 is provided with an operating system in 2K which handles the Acorn VDU, ASCII encoded keyboard and printer; it is readily expanded and very user friendly.

The hardware provides for direct plug-in connection to Anadex type printers and encoded keyboards and all 6809 signals are taken off the board via the Acorn bus 64 way edge connector. The address and data lines are buffered and 1K of user RAM is provided.

Hardware DIN standard indirect edge connector 20-way and 26-way I DC connectors for keyboard and printer MC 6809 microprocessor 2K ROM (Initially 2716) 4K and 8K compatible 1K RAM (2 x 2114) BIPOLAR PROM for address decoding 6522 - two 10-bit parallel 1/0 port for keyboard and printer Random logic devices Bus buffers The Acorn 6809 is provided with a User's Manual which describes how to use the Monitor's commands, and includes programming examples."




 200.012 Issue unknown [3 System 3]

6809 CPU Board Top Side Photo6809 CPU Board Track Side Photo

200.012 Issue unknown

6809 CPU Board Top Side Photo


Here is an image of the 2716 EPROM fitted to Chris Whytehead's System 3 [3], it is labeled 'MPROM 4A FEB 93 BS=08'

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