CODESG SEGMENT PARA 'CODE'
       ASSUME CS:CODESG, DS:CODESG, SS:CODESG, ES:CODESG
       ORG    100H

MAIN   PROC   NEAR
       PUSH   CX
       PUSH   AX
       XOR    CX, CX
       MOV    CL, 3FH
L1:
       MOV    AL, CL
       OUT    70H, AL
       JMP    L2
L2:
       OUT    71H, AL
       LOOP   L1

       POP    AX
       POP    CX
MAIN   ENDP

CODESG ENDS
       END  MAIN