It is electrically different to the 6800 not to confuse the two chips,
different clock etc
There was a Rockwell version too
Dave Caroline
On 16/08/2014, Sean Caron <scaron at umich.edu> wrote:
Hi A.P,
The data sheets are out there; I've seen about three different datasheets
for the 6502 floating around, one is the original MOS preliminary, there's
a Synertek one, and there's the brand new one from WDC. I'm sure you could
find more if you hunted around.
It's all the same op-codes and addressing modes; except in the currently
shipping 65C02(S) they added a few instructions and filled out a few pins
that aren't present in the earlier revs. So if you are working with an
older 6502, use the older datasheet; if you just went out and got a brand
new one from WDC, use the new data sheet.
Other than that, any old 6502 data sheet is about as definitive as it gets
:)
If you are talking about assembler macros and stuff like that, I'm sure
there are as many variants as there were assemblers, little to no
standardization there from my experience, LOL. But regardless of the
computer, it's the same 6502 and same op-codes underneath.
I'm in the middle of doing a little 6502 SBC right now so I've been poring
through these publications quite a bit over the course of the last few
weeks ;)
Another neat reference is 'The 6800 Processor' by Jack Quinn, I know it's
not 6502-specific but the two CPUs were so similar, there's a lot of
relevance... nice book discussing the programming model on these CPUs
including a very thorough treatment on hand-assembly which I found to be
quite educational.
Best,
Sean
On Sat, Aug 16, 2014 at 9:45 AM, A. P. Garcia <a.phillip.garcia at gmail.com>
wrote:
Was there more or less a standard or reference
6502 assembly language
(e.g.
from MOS) with regard to syntax and pseudo ops? With the cpu being used
in
so many different computers, and so many vendors writing their own
assemblers for each platform, did the assemblers tend to resemble each
other (besides the instruction set), or did everyone tend to do their own
thing?