Re: 65C02 emulation

[Mark McDougall <markm@vl.com.au>]

Charlie Springer wrote:

> I am fiddling with emulation on the ARM again. Does anybody know
> performance of various emulators? Right now, in simulation I come
> very close to a one-to-one cycle count with an interpreter. In other
> words, an itty bitty 60 MHz ARM chip should execute 65C02
> instructions equivalent to a 40 to 50 MHz 65C02.

What you're perhaps forgetting is that 'various emulators' do a lot more
than simply emulate the 6502 processor - they emulate the rest of the
apple hardware (including every memory access) and also render graphics
on the PC display. No doubt you could run a 6502 emulation on a 3.4GHz
wintel box at some blazing speed too...

So that you can emulate a 6502 on an 'itty bitty' ARM chip isn't that
surprising. When you've got it generating composite output and still
running at 40MHz, let us know! ;)

But the point isn't lost - I was looking at using the Cypress EZUSB to
interface to both the TRS-80 and the Apple, for example. That has an
8051 core running at (IIRC) 12 MIPS - running rings around both the 6502
and Z80 in the computers themselves. It all gets a bit ridiculous when
you think about it...

Regards,

-- 
Mark McDougall, Engineer
Virtual Logic Pty Ltd, <http://www.vl.com.au>
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266