[Coco] "Reading" non-readable bytes with PEEK vs ZBUG

[Roger Taylor]

At 07:38 AM 1/25/2008, you wrote:

>There is another approach which will be independent of memory but 
>not relocated DOS code. Write a Basic program as a LOADM routine for 
>your binary program.
>10 A=PEEK(&HC003)
>20 IF A=8 THEN POKE&HD008,&H21 ELSE POKE&HCF2C,&H21
>30 LOADM"ROGER.BIN"
>
>The only sure method would be to LOADM a routine to load the rest of 
>your binary without byte verification.



That was my 2nd idea, but I'd let LOADM do that poking.  If the BASIC 
program assumes those ROM addresses are the same on *all* CoCo 3's, 
them LOADM'ing those bytes into the RAM'ed ROM would work just as 
well and is the simplest idea.

I'm not sure what approach I'll use but I'm definately for the idea 
of self-contained games without requiring other files being readin at 
run-time.  Since CCASM allows for includebin "file.ext" to include 
anything on earth into the codestream, and include "file.asm", 
there's potential for power when coupled with writing to the MMU 
registers beforehand to stash away those includes before the game code starts.

I like the LOADM patch above probably more than anything else, 
assuming that it's compatible with all Disk BASIC variations.  If I 
have to require DIsk BASIC and a few people are left out, and they 
want to play the game bad enough, I'm sure they'll figure something 
out, but I'm aiming for across the board compatibility with my scheme 
and so far the no-patch/no-hack %01xxxxxx MMU trick seems to be ideal 
regardless of how many people seem to be worried about there being 
random noise in those bits for certain CoCo's.  Testing and time will 
tell, I guess.