王爽 汇编 实验12
主要思路: 1.将中断的处理程序以数据方式写入到内存中.(显示overflow字符串.)
2.修改中断向量表的值,使0号表项指向中断处理程序的开始地址
3.开始除法运算,引发除法溢出错误.
1 assume cs:codeseg 2 3 data segment 4 db 16 dup (0) 5 data ends 6 codeseg segment 7 start: 8 ;do0程序的安装,将do0程序写入到内存0:200处 9 mov ax,cs 10 mov ds,ax 11 mov si,offset do0 12 mov ax,0 13 mov es,ax 14 mov di,200h 15 mov cx,offset do0end-offset do0 ;算出cx要循环的长度 16 cld ;正向 17 rep movsb 18 19 ;将do0的入口地址送入中断向量表0号表中. 20 mov ax,0 21 mov es,ax 22 mov word ptr es:[4*0],200h ;低地址存放偏移地址 23 mov word ptr es:[4*0+2],0 ;高地址存放段地址 24 25 mov ax,1000h ;进行除法运算,引发除法溢出错误. 26 mov bh,1 27 div bh 28 29 mov ax,4c00h 30 int 21h 31 32 ;显示字符串 33 do0:jmp short do0start 34 db "overflow tri" 35 do0start: 36 mov ax,cs 37 mov ds,ax 38 mov si,202h 39 40 mov ax,0b800h 41 mov es,ax 42 mov di,12*160+36*2 43 44 mov bl,42h 45 mov cx,12 ;共12个字符 46 s: mov al,[si] 47 mov es:[di],al 48 mov es:[di+1],bl ;设置字符颜色为红底绿字 49 inc si 50 add di,2 ;一个字符占两字节.低位ASCII码.高位字符属性 51 loop s 52 53 mov ax,4c00h 54 int 21h 55 do0end:nop 56 57 codeseg ends 58 59 end start
