assume ds:data, cs:code data segment db 'welcome to masm!' db 2H,24H,71H data ends code segment start: mov ax,data mov ds,ax mov ax,0B800H mov es,ax mov cx,10h mov bx,0 mov si,0 s0:mov ax,[bx] mov es:[0720h+si+bx],ax mov al,2h mov byte ptr es:[0721h+si+bx],al inc bx inc si loop s0 mov cx,10h mov bx,0 mov si,0 s1:mov ax,[bx] mov es:[07c0h+si+bx],ax mov al,24h mov byte ptr es:[07c1h+si+bx],al inc bx inc si loop s1 mov cx,10h mov bx,0 mov si,0 s2:mov ax,[bx] mov es:[0860h+si+bx],ax mov al,71h mov byte ptr es:[0861h+si+bx],al inc bx inc si loop s2 mov ax,4c00h int 21h code ends end start 改成子程序形式

下面是将代码改写成子程序形式的程序：

assume ds:data, cs:code

data segment
    db 'welcome to masm!'
    db 2H,24H,71H
data ends

code segment
    start:
        mov ax,data
        mov ds,ax
        mov ax,0B800H
        mov es,ax

        call print_string_attr_1
        call print_string_attr_2
        call print_string_attr_3

        mov ax,4c00h
        int 21h

print_string_attr_1:
    mov cx,10h
    mov bx,0
    mov si,0

s0:
    mov ax,[bx]
    mov es:[0720h+si+bx],ax
    mov al,2h
    mov byte ptr es:[0721h+si+bx],al
    inc bx
    inc si
    loop s0

    ret

print_string_attr_2:
    mov cx,10h
    mov bx,0
    mov si,0

s1:
    mov ax,[bx]
    mov es:[07c0h+si+bx],ax
    mov al,24h
    mov byte ptr es:[07c1h+si+bx],al
    inc bx
    inc si
    loop s1

    ret

print_string_attr_3:
    mov cx,10h
    mov bx,0
    mov si,0

s2:
    mov ax,[bx]
    mov es:[0860h+si+bx],ax
    mov al,71h
    mov byte ptr es:[0861h+si+bx],al
    inc bx
    inc si
    loop s2

    ret

code ends

end start

以上程序将每个循环改写成了一个子程序，分别是print_string_attr_1、print_string_attr_2和print_string_attr_3。在主程序中调用这三个子程序即可完成字符串及属性值输出到80×25彩色字符模式显示缓冲区的操作。