汇编实验15

eol75999

1. assume cs:code
   
2. code segment
   
3. start:
   
4. mov ax,cs
   
5. mov ds,ax
   
6. mov ax,0
   
7. mov es,ax
   
8. 
   
9. mov si,offset int9
   
10. mov di,204
    
11. 
    
12. mov cx,offset int9end-offset int9
    
13. 
    
14. cld
    
15. rep movsb;写进0:204
    
16. 
    
17. push es:[9*4]
    
18. pop es:[200]
    
19. push es:[9*4+2]
    
20. pop es:[202]
    
21. 
    
22. cli
    
23. 
    
24. mov word ptr es:[9*4],204
    
25. mov word ptr es:[9*4+2],0
    
26. 
    
27. sti
    
28. 
    
29. mov ax,4c00h
    
30. int 21h
    
31. 
    
32. 
    
33. int9:
    
34. push ax
    
35. push bx
    
36. push cx
    
37. push es
    
38. 
    
39. in al,60h
    
40. pushf
    
41. call dword ptr cs:[200]
    
42. 
    
43. cmp al,1eh+80h;判断是否是a的断码
    
44. jne int9ret
    
45. mov ax,0b800h
    
46. mov es,ax
    
47. mov cx,4000
    
48. mov bx,0
    
49. 
    
50. s:
    
51. mov byte ptr es:[bx],'A'     
    
52. inc byte ptr es:[bx+1]
    
53. add bx,2
    
54. loop s
    
55. 
    
56. int9ret:
    
57. pop es
    
58. pop cx
    
59. pop bx
    
60. pop ax
    
61. iret
    
62. 
    
63. int9end: nop
    
64. 
    
65. code ends
    
66. end start

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