Verilog source code for a fully functional 6502 compatible cpu core.
Experimental Core - 32 bit bus interface 6502
The RTF65002 Project a 32 bit cpu with 65C02 emulation
Here is a 6502 macro assembler. It supports all the original 6502 instructions plus W65C02 instructions and is TASS compatible. It can produce a binary or S19 record compatible output. It's just called "asm" for lack of a better moniker. It is shareware and it'll cost $50 to get it to work for more than 45 days.
asm.zip (about 100k)
Picture of R65C02P2
2 MHz 6502
The following screen from: "The Complete Commodore Inner Space Anthology" by Karl Hildon with the author's permission.
http://www.cc65.org (compiler + tools)
http://c64upgra.de/c-one/ (C-One computer - C64 compatible upgrade)
- contains a listing of a reference manual for the Commodore machines.
Other 6502 cores
A 6502 core done by Arlett Ottens in Norway
Software For SoC's
Lee Davison's enhanced basic: http://mycorner.no-ip.org/6502/ehbasic/index.html