; Compare R0 and R1

          MOV  A, R0
          SUBB A, R1
          JZ R0EQR1

          ANL A, #0x080
          JZ R0GTR1
          JNZ R0LTR1

R0EQR1:   MOV P1, #0x0FF
          JZ CONTINUE

R0GTR1:   MOV P1, #0x000
          JZ CONTINUE

R0LTR1:   MOV P1, #0x0FF

CONTINUE: <i>Here's where the rest of your code picks up.</i>