standard 6502 syntax?

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: