首先申明不是小弟我生性懒惰，不过实在是再比较后找不出来，才贴出来找大家帮忙的，先谢过了
//+++++++++++++++++++++++++++++++++++++
;向0:200---0:23f传送数据0---63(3fh)
assume cs:codesg
codesg segment
mov ax,0
mov ds,ax
mov cx,40h
mov ax,200
mov bl,0
L: mov [ax],bl
inc ax
inc bl
loop L
mov ax,4c00h
int 21
codesg ends
end
//=================================================以上是错误的（在masm611中编译的）

.model small
.code
start:
mov ax,0
mov ds,ax
mov cx,40h
mov di,200
mov bl,0
L: mov [di],bl
inc di
inc bl
loop L
mov ax,4c00h
int 21h

end start

assume cs:codesg
codesg segment
mov ax,0
mov ds,ax
mov cx,40h
mov ax,200
mov bl,0
L: mov [di],bl
inc di
inc bl
loop L
mov ax,4c00h
int 21h
codesg ends
end

谢拉，问题已解决