1 assume cs:code 2  3 code segment 4 start: 5         mov ax,code 6         mov ds,ax 7         mov si,offset do0 8         mov ax,0 9         mov es,ax10         mov di,200h11         mov cx,offset do0end-offset do012         cld13         rep movsb14 15         mov ax,016         mov ds,ax17         mov word ptr ds:[0],200h18         mov word ptr ds:[2],019 20         mov ax,4c00h21         int 21h22 23    do0:24         jmp short do0start25    do0str:26         dw 127         db ‘divide error! ‘28    do0start:29         mov ax,cs30         mov ds,ax31         mov si,202h32 33         mov ax,0b800h34         mov es,ax35         mov di,7c8h36         mov cx,1437     ;    mov cx,ds:[202h]38    s:39         mov al,ds:[si+2]40         mov es:[di],al41         inc si42         add di,243         loop s44 45         mov ax,4c00h46         int 21h47 48         mov ax,ds:[202h]49         inc ax50         mov ds:[202h],ax51 52         push cx53         mov cx,554      ds0:55         push cx56         mov cx,0ffffh57      ds1:58         loop ds159         pop cx60         loop ds061         pop cx62 63         iret64 65    do0end:66         nop67 68 code ends69 end start