KEYLEFT    BIT    P1.0
   KEYRIGHT   BIT    P1.1
   LEDLEFT    BIT    P1.2
   LEDRIGHT   BIT    P1.3

     ORG   0000H
    LJMP  START
    ORG   0030H
    
START:SETB  KEYLEFT
      SETB  KEYRIGHT
LOOP: MOV  C,KEYLEFT
      MOV  LEDLEFT,C
      MOV  C,KEYRIGHT
      MOV  LEDRIGHT,C
      LJMP  LOOP
      END