Re: Modern, but fully compatible 6502?

Ed, there's another very impressive project based on the netlist from 
Visual6502: Andrew Holmes' Verilog 6502.

http://www.aholme.co.uk/6502/Main.htm

However, Andrew mentions that his project might have less backward 
compatibilty than Monta's where undefined NMOS opcodes are concerned, 
and AIUI those undefined opcodes were on the OP's wish list.


Speaking of undefined opcodes, the 65C02 (ie, CMOS) has some 
underappreciated potential in that department.  This applies both to 
hardware hacking and to software shenanigans, but it's the 
hardware-hacking potential that's a real eye-opener, IMO!

Questions and comments are welcome, as 'C02 undefined opcodes are the 
focus of my recently published update to Bruce Clark's article on 
6502.org:

http://6502.org/tutorials/65c02opcodes.html#9

  -- Jeff  ( Dr Jefyll on 6502.org )


On 2022-09-04 14:43, Ed Spittles wrote:
> I've just remembered - one of the early successes from the visual6502
> project was Peter Monta's implementation of the core algorithm on an
> FPGA, running fast enough to work as a 1MHz 6502 in an Atari, using a
> GODIL module.