Re: 8502 vs 6510 undoc. opcodes

From: silverdr_at_srebrnysen.com Date: Thu, 12 Oct 2023 21:41:43 +0000 Message-Id: <679A492B-D0B8-4E5D-8B1E-440F368B06A5_at_srebrnysen.com>

>> On Thu, Oct 12, 2023 at 3:44 PM <silverdr_at_srebrnysen.com> wrote:
>> Are 8502 undocumented opcodes generally compatible with 6510 ones?
> 
> On 12 Oct 2023, at 21:03, Craig Taylor <ctalkobt_at_gmail.com> wrote:
> 
> For the most part, I believe so - however when doing the C= Hacking Undocumented opcodes I was originally on a 128 - and that may have introduced some of the issues that were reported about the table I created (that, and potentially interpretation - "one of these days" I'd like to do it w/ UTF8 w/o having to resort to psuedo logic symbols).  

I see. The reason I ask is that I always thought that C128 compatibility with C64 (and that unfortunately has to include undocumented opcodes) was on the 99-ish percentage level but got hit with an "undocumented don't run as expected" argument. As I don't know much about the 8502, I assumed it's still an HMOS-II, similar to 8500 so it should behave, shouldn't it?