循環無法打印字母 (Loop does not work to print alphabets)

問題描述

循環無法打印字母 (Loop does not work to print alphabets)

我正在使用 emu8086 彙編程序，我是彙編語言的新手。我想以黑色背景的黃色打印所有 AZ 字母。我的循環不工作。它一直在運行，只顯示 B 字母。 有人可以幫我嗎？這是我的代碼：

include emu8086.inc
ORG 100h
MOV AX,0B800h
MOV DS,AX
MOV CX,26
ALPHABETS:
MOV CL,41h
ADD CX,1
MOV CH,00001110b
MOV BX,0x0000
MOV [BX],CX
loop ALPHABETS
RET

參考解法

方法 1:

Your program has 2 problems:

• You use the CX register for both the loop counter and the character that you want to display.
• You forget to update the address in the BX register and so everything gets displayed on top of each other.

First solution using CX as a loop counter:

include emu8086.inc
ORG 100h
    MOV     AX, 0B800h
    MOV     DS, AX
    mov     al, "A"       ;First character
    mov     ah, 00001110b ;YellowOnBlack
    mov     bx, 0         ;Address in video RAM
    mov     cx, 26
ALPHABETS:
    mov     [bx], ax
    inc     al            ;Next character
    add     bx, 2         ;Next address
    loop    ALPHABETS
    RET

Second solution using the character code itself as a loop counter:

include emu8086.inc
ORG 100h
    MOV     AX, 0B800h
    MOV     DS, AX
    mov     al, "A"       ;First character
    mov     ah, 00001110b ;YellowOnBlack
    mov     bx, 0         ;Address in video RAM
ALPHABETS:
    mov     [bx], ax
    inc     al            ;Next character
    add     bx, 2         ;Next address
    cmp     al, "Z"
    jbe     ALPHABETS
    RET

(by user7056520、Sep Roland)

參考文件

1. Loop does not work to print alphabets (CC BY‑SA 2.5/3.0/4.0)