[这是我尝试在程序集8086上编写的代码,就像在普通键盘上一样,但是每次我按Enter时,它都会下降一行并在RAM中写入第二个字母,我如何在不复位的情况下修复它ram允许用户从键盘进行书写。
data segment
; add your data here!
msg db ?
nxtline db 10,13,'$'
ends
stack segment
dw 128 dup(0)
ends
code segment
start:
; set segment registers:
mov ax, data
mov ds, ax
mov es, ax
; add your code here
xor ax,ax
mov ah,1
xor bx,bx
mov bx,offset msg
ifpressed:
;pusha
mov ah,1
int 21h
cmp al,0Dh ;check when enter is pressed
jz nextline
mov [bx],al
add bx,2
;popa
jmp ifpressed
nextline:
lea dx, nxtline
mov ah, 9
int 21h
jmp ifpressed
reapet:
mov ax, 4c00h ; exit to operating system.
int 21h
ends
end start ; set entry point and stop the assembler.
`
...但是每当我按Enter时,它就会下降一行...
这正是程序创建的目的。如果您不希望发生这种情况,请从程序中删除下两行:
cmp al,0Dh ;check when enter is pressed
jz nextline
或保留这两行,但更改nxtline的定义(删除13):
nxtline db 10,'$'
它对我的BIOS中断汇编器不起作用,我认为它对dos汇编器有效。尝试通过更改dl和dh寄存器来手动更改列和行,如下所示:
Prompt: mov si, PromptChar
mov ah, 2
mov dh, 15 # change row to 15
mov dl, 0 # change column to 0
int 10h
lodsb
mov ah, 9
int 10h
jmp short End