Re: 65C02 emulation

["RedskullDC" <RDC@oz.org>]

Hi Charlie,
........
> Of course, this means a nice 520 MHz StrongARM should be like a 400 MHz
> 65C02. On a card in an Apple slot, it has to slow down to original speed 
> for
> various address ranges, but the rest of the time? In an Apple //e 
> emulation,
> quite a number of calls, like 16 and 32 bit math, could be mapped to 
> single
> instructions ....

Assuming that you may want to make it run 65816 code at some point, you
can really only add extra instructions via the WDC instruction.

Settling on two bytes for the new instructions, with WDC as the first
byte gives you a handy 256 new instructions.
Same as the CBxx, DDxx, and EDxx instructions in a Z80.

Good luck with the project,
Red