chengxu_01_05.asm

响铃程序（从键盘接收输入字符

DATAS SEGMENT
    
    MESSAGE DB 'PLEASE INPUT A NUMBER TO RING$'  
DATAS ENDS

STACKS SEGMENT
    STACKS ENDS

CODES SEGMENT
    ASSUME CS:CODES,DS:DATAS,SS:STACKS
START:
    MOV AX,DATAS
    MOV DS,AX
    PRINT:  MOV AL,9
        LEA DX,MESSAGE
        INT 21
        
        MOV AH,01H  
        INT 21H
        
        CMP AL,3AH  
        JNL PRINT       
         
         CMP AL,30H      
        JL PRINT      
        
        MOV CX,0000H
        AND AX,00FFH
        MOV CL,AL
        SUB CX,30H
        MOV DL,01H
AGAIN:  MOV AH,02H
        INT 21H
        LOOP AGAIN
    
    
    MOV AH,4CH
    INT 21H
CODES ENDS
    END START