p77_3.asm

本程序是汇编语言的一些基本功能的组合

DATA SEGMENT
  H DW 0
  STR1 DB 'Input Num(0-9):$'
  STR2 DB 13,10,'ERROR!$'
DATA ENDS
CODE SEGMENT
  ASSUME CS:CODE,DS:DATA
START: 
  MOV AX,DATA
  MOV DS,AX
  LEA DX,STR1
  MOV AH,9
  INT 21H
  MOV AH,1
  INT 21H
  CMP AL,'0'
  JB ERROR
  CMP AL,'9'
  JA ERROR
  SUB AL,30H
  MOV BL,AL
  MUL BL
  MUL BL
  MOV H,AX
  JMP EXIT
ERROR:
  LEA DX,STR2
  MOV AH,9
  INT 21H
EXIT:
  MOV AH,4CH
  INT 21H
CODE ENDS
  END START