安装程序：

 assume cs:code

 //jmp near ptr 标号指令的替代实现,使用iret指令

 code segment

     start:

           mov ax,cs

           mov ds,ax

           mov si,offset sub1

           mov ax,0020h

           mov es,ax

           mov di,

           mov bx,offset sub2 - offset sub1

           cld

           rep movsb

           mov ax,

           mov es,ax

           mov word ptr es:[7ch*],200h

           mov word ptr es:[7ch*+],

           mov ax,4c00h

           int 21h

      sub1:

           push bp

           mov bp,sp

           cmp bx,-32768 //近转移最小值偏移

           jl s0 //有符号数小于则转移

           cmp bx,32767 //近转移最大值偏移

           jg s0 //有符号数大于则转移

           add [bp+],bx //加上两转的偏移即可得到转移目标地址

        s0:

           pop bp

           iret

      sub2:

           nop

 code ends

 end start

 测试程序：

 assume cs:code

 //将数据段的数据显示屏幕上

 data segment

     db 'conversation',

 data ends

 code segment

     start:

           mov ax,data

           mov ds,ax

           mov si,

           mov ax,0b800h

           mov es,ax

           mov di,*

         s:

           cmp byte ptr [si],

           je ok

           mov al,[si]

           mov es:[di],al

           inc si

           add di,

           mov bx,offset s - offset ok

           int 7ch //安装程序

        ok:

           mov ax,4c00h

           int 21h

 code ends

 end start