assembly - x86 控制台滚动后出现奇怪的打印

Question

我有以下功能:

printRows proc
    mov cx, 25
    printRowsLoop:  
        mov si, 0
        printSingleRowLoop:

            mov ah, 3  ;save current cursor position  at dx (dh:dl)
            int 10h

            push dx ;keep the position for later

            mov ah, 2
            mov dl, '&'   
            int 21h      ; print '&' char in the current curser position

            pop dx   ; restore dx

            add dl, 5 ; increase the column of it with a const number (so it would look like a square)
            mov ah, 2
            int 10h

            inc si
            cmp si, 3 ; print 3 '&' in each row
            jne printSingleRowLoop 

        mov dl, 13     ; result of these 3 groups of commands should be 2 new lines
        mov ah, 2
        int 21h

        mov dl, 10
        ;mov ah, 2 ; ah is alredy 2
        int 21h

        ;mov dl, 10 ; dl is already 10
        ;mov ah,2  ; ah is already 2
        int 21h

        loop printRowsLoop  ; print (cx) lines 
    ret

printRows endp

它的输出应该是在 this screenshot 中看到的 - 这就是它的输出(至少在开始时)

但是，在“好”输出填充控制台后(当需要“滚动”时)，它不再打印每个 '&' 之间的空格，而是仅在新行 as can be seen here 中打印每个空格。

什么可能导致这种奇怪的行为？我究竟做错了什么？我该如何解决这个问题？

我使用的是emu8086。

Answer 1

您应该最后打印回车符(13 ascii 代码)。

我还包括了 Fifoernik我的回答中的提示。

printRows proc
mov cx, 25
printRowsLoop:  
    mov si, 0
    printSingleRowLoop:

        push cx
        mov bh, 0
        mov ah, 3  ;save current cursor position  at dx (dh:dl)
        int 10h  
        pop cx


        push dx ;keep the position for later

        mov ah, 2
        mov dl, '&'   
        int 21h      ; print '&' char in the current curser position

        pop dx   ; restore dx

        mov bh, 0
        add dl, 5 ; increase the column of it with a const number (so it would look like a square)
        mov ah, 2
        int 10h

        inc si
        cmp si, 3 ; print 3 '&' in each row
        jne printSingleRowLoop 


        mov dl, 10
        ;mov ah, 2 ; ah is alredy 2
        int 21h

        ;mov dl, 10 ; dl is already 10
        ;mov ah,2  ; ah is already 2
        int 21h

        mov dl, 13    ; <<<<<<<<<<<<<<<<<<<<< print the carriage return last!
        ;mov ah, 2 ; ah is already 2 
        int 21h  

    loop printRowsLoop  ; print (cx) lines 
ret

printRows endp

不需要额外的空格字符:)