I got my hands on a W65C802S P4 chip.

What is this chip ? Does it run at 4MHz ?

Thanks
Rob

I'd suggest shooting an email off to Westerndesign thru their website at

http://www.westerndesigncenter.com/

They reference that chip in one of their data sheets, but the don't seem to say much else about it.

Or perhaps someone who has used this chip might be able to post about it? I think Garth Wilson used one in one of his projects that is listed on this site.

_________________
-Tony
KG4WFX

The '802 is a 65816 made to drop into a 6502 socket. IOW, you get a lot of the benefits of the '816 with existing '02 hardware. You won't get the benefit of a 24-bit (16MB) address space, and the 24-bit addressing modes will be pointless; but you still get the accumulator that can switch between 8 and 16 bits as can the index registers, a 16-bit stack pointer and stack-relative addressing, memory block move instructions, relocatable base page (so it doesn't have to be zero page), easier multitasking and re-entrant, recursive, and relocatable code, and probably several other things I'm forgetting right now.

The '802 and '816 come out of reset in emulation mode, meaning they emulate a 65c02 until you clear the E (emulation bit) in the status register. Even in native ('816) mode, they would run most 6502 code with little or no modification as long as you keep the accumulator and index registers at 8-bit, so you can get into it slowly as you learn the new capabilities.

The '802 is not being made anymore AFAIK. The "-4" on the end does mean 4MHz. I have my Forth kernels in both '02 and '816 versions, and the the '816 version runs 2-3 times as fast at a given clock speed. You wouldn't get any benefit if you just ran the '02 version on the '816 (or '802), but the '816 version takes advantage of the added instructions and addressing modes to get the job done with fewer instructions and clock cycles.