GetStringLength:
; INPUT: A3 = BASE ADDRESS OF STRING
; RETURNS LENGTH IN D1 (MEASURED IN BYTES)
MOVE.L #0,D1

loop_getStringLength:

MOVE.B (A3)+,D0
CMP #0,D0
BEQ done
ADDQ.L #1,D1
BRA loop_getStringLength

done:
RTS