I loved the 6502. Around that era I programmed the SC/MP, Z80, the 8080 and the 6800. Although the Z80 was more powerful, the 6502 holds a special place in my heart as it was the first CPU I worked with and I loved the simplicity of the instruction set.

My crowning achievement was a multi-threaded kernel for a CNC punch. Since the stack was at a fixed memory address and there was no PUSHA, I had to change threads (in response to an IRQ) by sequentially pushing the registers on to the stack and then swapping the stack with a block copy. It worked! Crazy :/

I loved reading this article - thanks for posting. Awesome stuff! Makes me want to code my own circuit emulator :)