ùúùú¬¬¬¬¬¬¬¬¬¬**************************************************************************** * * * Convert HEX string to binary. * * * * Inputs: a0 = Pointer to string * * Outputs: Z = Success/Failure, d1 = Result * * * **************************************************************************** HexStrToBin: move.l a0,a1 ; Save pointer in a1 moveq #8,d0 ; 8 = MaxLength .Loop1: tst.b (a0)+ ; Check for end of string dbeq d0,.Loop1 bne.b .Error ; Error if end not found moveq #0,d1 ; Clear Result .Loop: move.b (a1)+,d0 ; Get character beq.b .End ; Quit if zero byte rol.l #4,d1 ; Rotate Result cmp.b #'0',d0 ; Check if ASCII '0' blt.b .Not09 cmp.b #'9',d0 ; to ASCII '9' bgt.b .Not09 sub.b #'0',d0 ; Subtract to get hex number or.b d0,d1 ; Put the number in the result bra.b .Loop .Not09: bset #5,d0 ; Convert to lowercase cmp.b #'a',d0 ; Check if ASCII 'a' blt.b .Error ; to ASCII 'f' cmp.b #'f',d0 ; Otherwise the character is not bgt.b .Error ; allowed. sub.b #'f'-$f,d0 ; Subtract to get hex number or.b d0,d1 ; Put the number to the result bra.b .Loop .Error: moveq #-1,d0 .End: rts