From Hamsterworks Wiki!
A clone of a 6502 processor
This FPGA Project was started June 2011. Has been put on hold as there exists plenty of 6502 clones, and there is very little merit in creating a new one.
The MOS 6502 and derivatives were used in many classic 8 bit micros. The Apple ][, the Commodore 64, BBC Micro...
I learned to program a 6502 in hex on a VIC 20 at around 1983. As a bug would usually need a hard reset I am very surprised that actually got any code working.
The original 6502 was in 1975, I want to see how hard it is to build one 35 years later!
The best background for somebody unfamiliar with the 6502 is http://en.wikipedia.org/wiki/MOS_Technology_6502.
Just a twinkle in my eye.
The instruction set is documented at http://e-tradition.net/bytes/6502/6502_instruction_set.html