任务：将beg_copy到end_copy的代码复制到0:200H处

assume cs:codeseg
codeseg segment
start:
...
beg_copy:
mov ax, 0
add ax, ax
wait
end_copy: nop

codeseg ends
end start

参考解答：

assume cs:codeseg
codeseg segment
start:
mov ax, cs
mov ds, ax
mov si, offset beg_copy

mov ax, 0
mov es, ax
mov di, 200H

mov bx, offset end_copy

copy: cmp si, bx
jnb stop_copy
mov al, [si]
mov es:[di], al
inc si
inc di
jmp copy
stop_copy:
mov ax, 4c00h
int 21h

beg_copy:
mov ax, 0
add ax, ax
wait
end_copy: nop

codeseg ends
end start