DATA SEGMENT
D1 DB 'A'
D2 DB 'B'
RES1 DB 'YES','$' ;结果提示符
RES2 DB 'NO','$' ;结果提示符
DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA
START:MOV AX,DATA
MOV DS,AX
MOV AL,D1 ;AL<--字符1
...