Programming $66

[Eric Aos]

Would searching for the starting address in the code be a starting place
then? The address would be loaded into the X register before the LDX or
whatever command is used right? 

Dave Zug wrote:

[SNIP]

> If the position contains data, it (again.. OR a byte preceeding it or 
> many bytes preceeding it) will be referenced most commonly by LDX, 
> (less commonly as LDY) or LDA or CMP or CMPA or many others including 
> the BITwise compares. other techniques involve loading X, 
> pushing offsets to stack, executing other code, adding stack offsets 
> to X and calling subrt's that use X or other.
> 
> I followed one such trail and said "okay this is hard" and gave up 
> that trail.
> 
> in short, JSR's point to code, LD* points to data. sometimes there is 
> DATA in the code section as well though! I can't figger if this was 
> on porpose (true hardcoding or security??? naah) or lazyness ("just 
> put this code in the next available location"). depending on the 
> "era" and  technique used to drop it in it could take longer to hide 
> data in code.
> 
> 
> 
> > I am trying to get a handle on this.. could someone point me in the
> > right direction? 
> > If I think I've found a table in a 730 (Just so we are all 
> talking about
> > the same processor), that starts at an address of lets say 
> 0085. What Op
> > Code would I be looking for in the program to see where it 
> access this
> > data? 
> > Looking back through Programming $65 it would seem to be 
> 'CE  00 85'  (
> > or in assembly LDX 0085 ). But looking at the ECMGUY'S 
> dissasemblies it
> > looked like the should be JSR's instead.... What am I missing?
> > 
> > 
> > 
> ~~~
> Dave Z. www.delanet.com/~tgp
>