Re: Converting 6502 Asm to PIC

[Toinet <antoine.vignau@laposte.net>]

On 24 nov, 23:30, PIC Newbie <allenbsf6...@gmail.com> wrote:
>
> MESSAGE STR 'APPLE 2 FOREVER'
>
>
> MAIN  LDX #1     ;POINT TO FIRST ASC
> MESSLOOP:
>       LDA MESSAGE,X
>       CMP $32
>       BNE CONV
> SPACE JSR INT_WORD_DLY   ;DELAY 6 DOT ELEMENTS ~500MS
>       CLC
>       BCC SPACE_OK
> CONV  JSR CONVERT        ;CONVERT ALPHA-NUMERIC TO INDEX
> SPACE_OK:
>       INX
>       CPX #MESSAGE+1     ;END OF MESSAGE?
>       BCC MESSLOOP
>       RTS
>
> TIA,
>
> Allen

I would have written...
SPACE_OK:
      INX
      CPX MESSAGE     ;END OF MESSAGE?
      BCC MESSLOOP
      RTS
...instead of CPX #MESSAGE+1.
The length of the string is saved in the first byte of MESSAGE not the
second. Unless this is due to the assembler but I doubt it.

I have another question regarding $32. Is there a useful info saved on
zero page offset $32 or is it the space character (#32 or #$20)?

Thank you,
antoine