键盘输入显示字符串问题
下面的代码编译运行之后,按任意键退出,我都怀疑虚拟8086能不能运行这个程序了;最基本的字符串输入程序,需要具备下面的功能
;1.在输入的同时需要显示这个字符串
;2.一般输入回车符后,字符串输入结束
;3.能够删除已经输入的字符
;子程序参数
;dh 显示位置_行
;dl 显示位置_列
;ds:si 指向字符串的首地址,字符串以0结尾
assume cs:code
code segment
start:
call getstr
return:
mov ax,4c00h
int 21h
getstr:
push ax
getstrs:
mov ah,0
int 16h
cmp al,20h
jb nochar
mov ah,0
call charstack
mov ah,2
call charstack
jmp getstrs
nochar:
cmp ah,0eh
je backspace
cmp ah,1ch
je enter1
jmp getstrs
backspace:
mov ah,1
call charstack
mov ah,2
call charstack
jmp getstrs
enter1:
mov al,0
mov ah,0
call charstack
mov ah,2
call charstack
pop ax
ret
charstack:
jmp charstart
table dw charpush,charpop,charshow
top dw 0
charstart:
push bx
push dx
push di
push es
cmp ah,2 ;ah功能号大于2退出
ja sret
mov bl,ah
mov bh,0
add bx,bx
jmp word ptr table ;功能号跳转
charpush:
mov bx,top
mov ,al
inc top
jmp sret
charpop:
cmp top,0
je sret
dec top
mov bx,top
mov al,
jmp sret
charshow:
mov bx,0b800h
mov es,bx
mov al,160
mov ah,0
mul dh
mov di,ax
add di,dx
mov bx,0
charshows:
cmp bx,top
jne noempty
mov byte ptr es:,' '
jmp sret
noempty:
mov al,
mov es:,al
mov byte ptr es:,' '
inc bx
add di,2
jmp charshows
sret: ret
code ends
end start 运行进入死循环
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