非法的指导

Question

.MODEL SMALL
.STACK
.DATA

LINE1 DB "Full Name: Random Guy$"
LINE2 DB 0,10, "Student ID: 2014-081289$"
LINE3 DB 0,10, "Course: Information Technology$"
.CODE
start:
MOV AX, @DATA
MOV DS, AX
MOV AH, 09h
MOV DX, OFFSET LINE1
INT 21h
MOV AH, 09h
MOV DX, OFFSET LINE2
INT 21h
MOV AH, 09h
MOV DX, OFFSET LINE3
INT 21h
INT 20h

END start

当我运行程序时，它指出LAB5.asm（9）非法指令。知道问题是什么吗？