[AlexCoventry]

I learned assembly on a TRS-80 Color Computer (6809 CPU.) Interactions with the machine were fairly straightforward.

[Sindisil]

The 6809 was a joy to program in assembly language. I enjoyed some aspects of Z80, and loved the puzzle of getting things done with 1802 and 6502, but 6809 was, for me, the sweet spot.

[osullivj]

Two stack pointers, one for call/return, the other for push pop data.