程序运行后,在第一行提示"Please Enter a Decimal Number:"
接收从键盘键入的一个介于0~65535之间的十进制数,以非数字字符作为输入结束标志;
将此十进制数转化成二进制数,存放在BX寄存器中;
若此数为0,则退出程序;若此数不为0,在下一行显示"The Hexidecimal is "和它的十六进制格式表示值;
返回程序开始处,再次显示输入提示;
十进制数输入过程/十六进制数显示过程/回车换行用子程序实现.
程序代码
.model small
.data
array1 db 5 dup(0)
msg1 db "Please Enter a Decimal Number:",'$'
msg2 db "The Hexidecimal is ",'$'
.code
.startup
JMP print_str
MOV AX,@DATA
MOV DS,AX
print_str:;打印第一行字
LEA DX,msg1
MOV AH,9
INT 21H
MOV BX,0
JMP input_num
input_num:;输入数字
MOV AH,1
INT 21H
MOV AH,0
MOV CL,0
JMP judge1
judge1:;判断ascii>30H(0)
CMP AL,30H
JNC judge2
JMP done
judge2:;判断ascii<=3AH(9)
CMP AL,3AH
JC save_num
JMP done
save_num:;将输入的数字拼成整数
INC CH
MOV CL,AL
SUB CL,30H
MOV AX,BX
MOV DX,10
MUL DX
MOV BX,AX
ADD BL,CL
MOV AX,0
CMP CH,5
JB input_num
JMP done
convert_num:;10->16进制转换
MOV DX,0
MOV AX,BX
MOV CX,10H
DIV CX
MOV BX,AX
CMP DX,0AH
JB ascii_num
JMP ascii_alphabet
ascii_num:
ADD DX,30H
JMP reverse_num
ascii_alphabet:
ADD DX,37H
JMP reverse_num
reverse_num:;余数逆序存储进数组,5,4,3,2,1
DEC SI
MOV [SI],DL
CMP BX,0
JBE done_arr
JMP convert_num
done_arr:
LEA SI,array1
JMP print_arr
print_arr:;打印数组
ADD SI,1
CMP Byte PTR [SI],0H
JE print_arr
MOV AH,2
MOV DL,Byte PTR [SI]
INT 21H
CMP SI,offset array1+4
JE quit
JMP print_arr
done:;输出第二行文字并准备数字转换
CMP BX,0
JBE quit
MOV AH,02H
MOV DL,0DH
INT 21H
MOV AH,02H
MOV DL,0AH
INT 21H
LEA DX,msg2
MOV AH,9
INT 21H
LEA SI,array1
ADD SI,5
JMP convert_num
quit:
.exit
end
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