Re: This is what I spend New Year's Eve doing

Em qua., 31 de dez. de 2025 às 21:14, Allen Huffman via Coco <
[email protected]> escreveu:

> On Dec 31, 2025, at 4:39 PM, William Astle via Coco <
> [email protected]> wrote:
>
> RVEC12 called from A390 is the most direct. Unfortunately, it looks like
> you'll have to fully duplicate the routine because you need to replace the
> "JSR $A171" at A39A with "JSR $A176".
>
> Alternatively, you could do a hack with RVEC4 where you detect if the
> return address $A173 and if so, change that to $A175 which can be done
> without burning any registers that need to be preserved). That skips over
> the "anda #$7f".
>
> You might be intercepting RVEC12 for something like fancy keyboard
> controls for immediate mode anyway which may make that option better.
> Otherwise, the second option requires less code duplication.
>
>
> This sounds like a similar issue to my console move character routine. I
> only wanted it to do that when you did a LIST rather than typing things in.
>

The CoCo ROMs are full of these
inspect-stack-and-do-this-only-if-it-was-XYZ-who-called-me shenanigans.
Quite seizure-inducing. Love it.

-- 
Coco mailing list
[email protected]
http://listserv.adelphi.edu/cgi-bin/mailman/listinfo/coco