编程将8253/8254计数器0设置为模式1,计数初值为3000H;答:MOV AL,23H 8253数器0 OUT O3H,AL MOV AL,3OH OUT 00H,AL MOV AL,75H 8253计数器1 OUT 03H,AL MOV AX,2010H OUT OOH,AL MOV AL,AH OUT 00H,AL MOV AL,0B9H 8253计数器2 OUT 03H,AL MOV AX,4030H OUT OOH,AL MOV AL,AH OUT 00H,AL 哪有8253计数器3啊???就是8254...