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

[Robert Gault]

Roger Taylor wrote:
> 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"
> 
> 
> 
> I now see that you're checking a byte first.  I didn't notice that 
> earlier, sorry.
> 
> 

That test distinguishes DOS1.0 from DOS1.1. Far as I know other third 
party DOS variations have not moved the LOADM code so the POKEs should 
work, but that is speculation.

As for self contained, RUN"Roger" is no harder to enter than 
LOADM"Roger". And regards the %01xxxxxx trick, it won't work well if the 
Coco has more than 512K RAM because it will change the required Vertical 
Offset Register values.