汇编学习（八）8086汇编拾遗 (7)

￡神魔★判官ぃ 2022-08-22 15:14 216阅读 0赞

int 中断指令
    
    使用方式：
    
    int n.  n 为中断类型码，它的功能是引发中断，n 为引发的中断号。
    
    先写一个中断程序的例子吧，安装中断7ch 中断例程，计算一个字型数的平方。

assume cs:code code segment start: mov ax,cs mov ds,ax mov si,offset sets mov di,200h mov ax,0 mov es,ax mov cx,offset sets0 - offset sets cld rep movsb mov ax,0 mov es,ax mov word ptr es:[7ch*4],200h mov word ptr es:[7ch*4 + 2],0 mov ax,4c00h int 21h sets: mul ax iret sets0:nop code ends end start

再来一个转换字符串的中断。 功能：将一个全是子母，以0结尾的字符串转换为大写。

assume cs:code
    
    code segment
    
        start:
            mov ah,2
            mov bh,0
            mov dh,5
            mov dl,12
            int 10h
            
            mov ah,9
            mov al,'a'
            mov bl,11001010b
            mov bh,0
            mov cx,3
            int 10h
    
    
            mov ax,4c00h
            int 21h
    
    code ends
    end start

使用int 模拟 loop

assume cs:code
    
    code segment
        start:
            mov ax,cs
            mov ds,ax
            mov ax,0
            mov es,ax
            mov si,200h
            mov di,offset se
    
            mov cx,offset se0 - offset se
    
            rep movsb
    
            mov ax,0
            mov es,ax
            mov word ptr es:[7ch*4],0
            mov word ptr es:[7ch*4+2],200h
    
            mov ax,4c00h
            int 21h
    
        se:
            push bp
            mov bp,sp
            dec cx
            jcxz ll
            add [bp+2],bx
        ll:
            pop bp
            iret
    
        se0:
            nop
    
    code ends
    end start

编写7CH中断实现jmp near ptr s   功能：

assume cs:code
    
    data segment
    
        db 'conversion',0
    
    data ends
    
    code segment
    
        start:
            mov ax,cs
            mov ds,ax
            mov si,offset se
            mov ax,0
            mov es,ax
            mov di,200h
            mov cx,offset se0 - offset se 
    
            rep movsb
    
            mov ax,0
            mov es,ax
            mov word ptr es:[7ch*4],200h
            mov word ptr es:[7ch*4+2],0
            
            mov ax,data
            mov ds,ax
            mov si,0
            mov ax,0b800h
            mov es,ax
            mov di,12*160
          s:
            cmp byte ptr [si],0
            je ok
            mov al,[si]
            mov es:[di],al
            inc si
            add di,2
            mov bx,offset s - offset ok
            int 7ch
         ok:
            mov ax,4c00h
            int 21h
    
    
        se:
            push bp
            mov  bp,sp
            add  [bp+2],bx
            pop bp
            iret
    
        se0:nop
    
    code ends
    end start

编写并安装7ch中断，直到0结束的字符串

assume cs:code
    
    data segment
    
        db 'weclome to linux world!',0
    
    data ends
    
    code segment
    
        start:
            mov ax,cs                ;添加中断代码
            mov ds,ax
            
            mov si,offset se 
            mov di,200h
    
            mov ax,0
            mov es,ax
            mov cx,offset se0 - offset se 
            
            cld 
            rep movsb
    
            mov ax,0                 ;设置中断号
            mov es,ax
            mov word ptr es:[7ch * 4],200h
            mov word ptr es:[7ch * 4 + 2],0
        
            mov dh,10                ;测试代码
            mov dl,10
            mov cl,2
            mov ax,data
            mov ds,ax
            mov si,0
            int 7ch
    
    
    
            mov ax,4c00h
            int 21h
    
        se:
            mov al,160           ;设置es:0b800h         
            mul dh
            add dl,dl
            mov dh,0
            add ax,dx
            mov di,ax
            mov ax,0b800h
            mov es,ax
          s:
            mov al,ds:[si]       ;打印字符
            mov ah,0
            cmp ax,0
            je f
            mov ah,cl 
            mov es:[di],ax
            inc si
            inc di
            inc di
            jmp s
          f:
            iret
    
        se0:nop
    
    
    code ends
    end start

编写7C 中断，打印80个!

assume cs:code
    
    code segment
    
        start:
            mov ax,cs                       ;安装中断
            mov ds,ax
            mov si,offset lp
    
            mov ax,0
            mov es,ax
            mov di,200h
    
            mov cx,offset lpend - offset lp
            cld
            rep movsb
    
            mov word ptr es:[7ch*4],200h
            mov word ptr es:[7ch*4 + 2],0
    
            mov ax,0b800h                   ;设置es
            mov es,ax
            mov di,160*12
            mov bx,offset s -offset se 
            mov cx,80
            s:
                mov byte ptr es:[di],'!'
                add di,2
                int 7ch
            se:
                nop
    
            mov ax,4c00h
            int 21h
    
            lp:
                push bp                     ;循环 
                dec cx
                jcxz f
                mov bp,sp
                add [bp+2],bx
            f:
                pop bp
                iret
            lpend:nop
    
    code ends
    end start

查看原文：[http://zmrlinux.com/2016/05/31/%e6%b1%87%e7%bc%96%e5%ad%a6%e4%b9%a0%ef%bc%88%e5%85%ab%ef%bc%898086%e6%b1%87%e7%bc%96%e6%8b%be%e9%81%97-7/][http_zmrlinux.com_2016_05_31_e6_b1_87_e7_bc_96_e5_ad_a6_e4_b9_a0_ef_bc_88_e5_85_ab_ef_bc_898086_e6_b1_87_e7_bc_96_e6_8b_be_e9_81_97-7]

[http_zmrlinux.com_2016_05_31_e6_b1_87_e7_bc_96_e5_ad_a6_e4_b9_a0_ef_bc_88_e5_85_ab_ef_bc_898086_e6_b1_87_e7_bc_96_e6_8b_be_e9_81_97-7]: http://zmrlinux.com/2016/05/31/%E6%B1%87%E7%BC%96%E5%AD%A6%E4%B9%A0%EF%BC%88%E5%85%AB%EF%BC%898086%E6%B1%87%E7%BC%96%E6%8B%BE%E9%81%97-7/