ORG  1000H
;MEMORIA
NUM DB 02
ROTA DB 03
RES  DB ?
;SUBRUTINAS
ORG 3000H
ROTARIZQ: PUSH BX
    MOV BX,SP
    PUSH AX
    PUSH CX
    PUSH DX
    ADD BX,6
    MOV CX,[BX]
    ADD BX,2
    MOV AX,[BX]
    CMP CX,0
    JZ FIN
ROTAR:  ADD AL,AL
  JNC SCARRY
  INC AX
SCARRY: DEC CX
  JNZ ROTAR
FIN: SUB BX,4  
  MOV DX,[BX]
  MOV BX,DX  
  MOV [BX],AL
  POP DX
  POP CX
  POP AX
  POP BX
  RET
;PROGRAMA PRINCIPAL
ORG 2000H
MOV AL,NUM
PUSH AX
MOV AL,ROTA
PUSH AX
MOV AX,OFFSET RES
PUSH AX
MOV AX,0
CALL ROTARIZQ
POP AX
POP AX
POP AX
HLT
END