; present date: 2005.4.30
; last modify date:2005.5.06
; auther      : yerunbin 
; ver         : 1.0

       .model small
       .stack
       .data
       fron db 01h                ;前景顏色
       backcolour db 00h          ;背景顏色
       heng db ?                  ;橫
       shu db ?                   ;列

       .code                      ;代碼段
begin:
        mov ax,@data
        mov ds,ax
        mov es,ax

        mov ah,00h                 ;設置顯示方式
        mov al,03h
        int 10h
                                   ;背景  
change: mov ah,02h                 ;設置光標位置
        mov bh,00
        mov dh,00                  ;第00行
        mov dl,00                  ;第00列
        int 10h

        add backcolour,10h         ;背景顏色改變          
        mov ah,09h                 ;在光標位置顯示
        mov al,20h                 ;顯示空白字符
        mov bh,00
        mov bl,backcolour
        mov cx,4000           ;重復4000次            
        int 10h
                                                           
again:  mov heng ,01         ;前景（A的右）
        mov shu, 39
right:  call require         ;調用函數require
        inc heng             ;行加1
        inc shu              ;列加1
        cmp heng,23                
        jne right

        mov shu,38            ;前景（A的左）
        mov heng,02
left:   call require          ;調用函數require
        inc heng                         
        dec shu               ;列減1 
        cmp heng,23
        jne left  
                              ;前景（A的中間）
        mov heng,15                    
        mov shu,26
mid:    call require
        inc shu
        cmp shu,53
        jne mid

        mov ah,02h             ;用2號中斷設置光標在25：80位置
        mov bh,00
        mov dh,24
        mov dl,79
        int 10h

key:    mov ah,07h
        int 21h
        cmp al,'1'
        je change
        cmp al,'2'
        je change2
        cmp al,41h             ;A
            jz exit   
        cmp al,61h             ;a
            jz exit   
        jmp key

change2:add fron ,01h
        jmp again

exit:   mov ax,4c00h         ;退出程序
        int 21h

require proc near            ;函數require
        mov ah,02h
        mov bh,00
        mov dh,heng
        mov dl,shu
        int 10h
        mov ah, 09h
        mov al,41h            ;顯示A
        mov bh,00
        mov bl,fron
        mov cx,01             ;在光標位置顯示1次
        int 10h
        ret
        require endp

        end begin