Altirra: How to use ;##TRACE to trace the accumulator, X and Y registers?

[freetz]

Hi everyone,

 

I love Altirra's ;##TRACE function and it works great with labels, but I can't find any info on how to trace the accumulator or the X/Y registers. I'm using ;## TRACE "Accumulator = %d" db(a) but it gives me strange values, the same goes for db(x) or db(y). If I store the register in a labelled memory location and trace that one, that's fine, but I want to do it directly. Does anyone know how?

 

[Teapot]

;##TRACE "%d %d %d" @a x y

[freetz]

Great, thanks! Is this documented anywhere where I could have looked it up?

[phaeron]

There's a section in the help file in recent versions for it (Debugger > Diagnostics), but it doesn't cover the specific details here since it just defers to the .printf command for how the arguments are interpreted. The debugger help for the ? command (.help ?) covers how debugger expressions work in general.

 

[freetz]

Thanks a lot! Is there a reason why the registers have to be accessed via @ and other memory locations can be accessed via db() etc.? And where were the values coming from that I got with db(y) for example? BTW, db(Y) would give me an error...

EDIT: Ok, after reading .help ? more thoroughly, with db(y), I probably got the contents of the memory location that the value of the Y-register was referring to.

And just FYI: .help ? mentions the X, Y, S, PC and P register, but not the A(ccumulator). Maybe it would be helpful to add. And in gerneral, a tutorial or text on how to use debugging with Altirra would be really great. I think I'm just using 5% of what Altirra is capable of, but that alone is already a huge life-saver, so I can only assume how much more power I'd have at my hands if I had a thorough introduction into all the other capabilities :)...

Edited February 15 by freetz