t3-12.asm

上课时老师讲的一些经典的例子；错过了就太可惜了呀

DSEG SEGMENT
     STRING DB 'HOW ARE YOu !',0
DSEG ENDS
;
CSEG SEGMENT
     ASSUME CS:CSEG,DS:DSEG

START:
       MOV AX,DSEG
       MOV DS,AX
       MOV SI,OFFSET STRING
AGAIN:
       MOV AL,[SI]
       OR AL,AL
       JZ OK
       CMP AL,'A'
       JB NEXT
       CMP AL,'Z'
       JA NEXT
       OR AL,20H
       MOV [SI],AL
NEXT:
       INC SI
       JMP AGAIN
OK:    MOV AX,4C00H
       INT 21H
CSEG   ENDS
       END START