Old 6809 Computer Lives Again On Breadboards

Old 6809 Computer Lives Again On Breadboards

Among old CPUs, the 6809 never got as much attention as some of its cousins. The Radio Shack CoCo used it and so did a construction article in Wireless World Magazine. Now [Dave] has reconstructed that computer on breadboards and it looks great. The files are on GitHub and there is even a series of videos about the machine. You can watch the first one below.

You can even read the original articles in the January 1981 Wireless World where the board used a 6802. The upgrade to a 6809 appears in the July 1981 issue. The magazine promised you could build the system for £100. Besides the 6809 there were only a few chips. A PROM, two RAM chips, A 6821 PIA, and a 74LS138 decoder for address selection. An MC1413 transistor array also allowed for a 7-segment display and a keypad along with a 7442 BCD decoder.

Apparently [Dave] had started a similar computer back in the 80s, and made changes to it to adapt to the Wireless World’s project memory map. It sounds like he didn’t finish it, but he found the old boards and decided to recreate it on a breadboard.

Like many computers of the day, the machine had a cassette interface. We really like the aesthetic of the 7-segment LEDs and the overall look of the build.

The 6809 did see use in some specific industrial and video game applications. There was also a New Zealand educational computer based on the 6809, along with a few other home computers like the SuperPET and the Dragon.