我一遍又一遍地得到同样的错误 . 我希望我是一个白痴，错过了一些我没有看到的巨大的东西 . 请帮我理解我做错了什么
错误A2006未定义符号：$ t1
.MODEL SMALL
.DATA
str: .asciiz "Name: Cristian Benitez"
.CODE
MAIN PROC
MOV AX, @DATA # intialize DS
MOV DS, AX
LA $a0, str
loop:
lbu $t1, 0($a0) # load the next character into t1
beqz $t1, exit # check for the null character
LEA DX, $t1
MOV AH,09H # to display one character at a time
INT 21H
addi $a0, $a0, 1 # increment the string pointer
j loop # return to the top of the loop
exit:
MAIN ENDP
END MAIN