Anyone use a WDC 65C02S?

[peteym5]

I have a similar post under Atari 8-bit. I am wondering if anyone had replaced the Atari custom CPU with the Western Design Centers 40 pin version w65c02s chip and had used it. Does it work on the Atari 8-bit motherboard in place of the original CPU. Something I remember that Atari 6502C version did special interrupt that allows the bus to pass control to the Antic chip. I would like to know if this is going to be an issue.

 

The advantages of this CPU would be is that it has a few extra instructions (OPCODES) and an extra addressing mode. Extra Opcodes include BRA, PHX, PHY, PLX, PLY, STZ, SRB (RMB), SMB. My Mac/65 cartridge supports some of these codes. It would give you some advantages like transferring the X, Y registers directly to the stack, come in handy with DLIs+VBIs. BRA is good for code that you need not to be in a specific location. New Addressing mode is Inderect without using the Y register. STZ comes in handy for clearing graphics on the screen and in the player/missile base. It may give us some better graphics and animations. Any ML code is going to be slightly shorter and requires less cycles to execute.

 

http://www.65xx.com/wdc/w65c02s-chip.cfm

 

I know it says it has a max speed of 14mhz, however going faster requires additional modifications do to limitations of the other ICs. I am just looking to run it at 1.79mhz. This upgrade is probably much cheaper than anything else that gives some advantages and it is already out there and available. One other advantage is the 65816 also has the same opcodes and any of those upgrades will be able to run anything written for this CPU.