6809 Assembly programming for the Dragon 32/64 and Tandy COCO

The Dragon is an odd beast! Using the impressive 6809 CPU, it somehow ends up being no better than it's 6502 competitors... part of the reason for this is it's clocked at less than 1mhz, and part is the limited RAM and Graphics of the system.

The Dragon 32/64 are virtually the same machine, and strangely, the Tandy COCO (TRS-80 COLOR) is also 99% compatible, for this reason we'll be covering them both here.

For simplicity, In these tutorials, we'll be looking at 32k systems, we won't cover the 4k/16k COCO



Dragon 32 Dragon 64 Tandy COCO (TRS-80 Color Computer)
Cpu 0.89mhz 6809
0.89mhz 6809 0.89mhz 6809
Ram 32k  64k 4k/16k/32k/64k
Max Resolution 128x192 @ 4 color (6k)
256x192 @ 2 color (6k)
128x192 @ 4 color (6k)
256x192 @ 2 color (6k)
128x192 @ 4 color (6k)
256x192 @ 2 color (6k)
Dragon 32
I am Dragon , hear me roar... Gao!