汇编程序50：检测点15.1(1) 

 1 assume cs:code
 2 ;在屏幕处显示字符'a'变化到'z',并随时接受按键esc变化其颜色属性
 3 stack segment
 4     db 128 dup(0)
 5 stack ends
 6 
 7 data segment
 8     dw 0,0
 9 data ends
10 
11 code segment
12     start:
13           mov ax,stack
14           mov ss,ax
15           mov sp,128
16 
17           mov ax,data
18           mov ds,ax
19 
20           mov ax,0
21           mov es,ax
22 
23           push es:[9*4]
24           pop ds:[0]
25           push es:[9*4+2]
26           pop ds:[2] ;把程序结束前需归还的原按键例程入口地址储存到数据段
27 
28           mov word ptr es:[9*4],offset int9
29           mov es:[9*4+2],cs ;设置中断例程入口地址
30 
31           mov ax,0b800h
32           mov es,ax
33           mov ah,'a'
34         s:
35           mov es:[12*160+40*2],ah
36           call delay
37           inc ah
38           cmp ah,'z'
39           jna s ;在屏幕上显示从字符'a'到'z'
40 
41           mov ax,0
42           mov es,ax
43 
44           push ds:[0]
45           pop es:[9*4]
46           push ds:[2]
47           pop es:[9*4+2] ;把原按键例程的入口地址归还给向量的中断向量表
48 
49           mov ax,4c00h
50           int 21h
51 
52     delay: ;延迟子程序
53           push ax
54           push dx
55           mov dx,10h
56           mov ax,0
57        s1:
58           sub ax,1
59           sbb dx,0
60           cmp ax,0
61           jne s1
62           cmp dx,0
63           jne s1
64           pop dx
65           pop ax
66           ret
6x
67      int9: ;新int9中断例程
68           push ax
69           push bx
70           push es
71 
72           in al,60h //从接口卡芯片处等待接受按键信息
73 
74           pushf
75           call dword ptr ds:[0] ;精简的2行代码
76           cmp al,1
77           jne int9ret
78           mov ax,0b800h
79           mov es,ax
80           inc byte ptr es:[12*160+40*2+1] ;字符颜色变化
81 
82   int9ret:
83           pop es
84           pop bx
85           pop ax
86           iret
87 
88 code ends
89 
90 end start

 

posted on 2018-02-04 20:13  叶倾仙  阅读(508)  评论(0)    收藏  举报

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