使用DVCC实验系统中的并行接口芯片8255A的B口作输入口，使工作于方式1,将PB0～PB7连接到手动开关K1～K8,将手动脉冲信号SP作为8255B口的选通信号，连接到PC2。将B品工作于方式1时的中断请求信号（PC0）连接到8255A的IR3,8255A的片选信号无需连接（系统已连接好）。8259A的CS连接地址译码输出端Y6,8259A的端口地址为60H、61H-DVCC experimental system used in parallel interface chip 8255A for the B input port, so that work in one way, will be connected to the PB0 ~ PB7 manually switch K1 ~ K8, the manual pulse signal SP population as 8255B Strobe, connect to PC2. B goods will work in one way at the time of interrupt request signals (PC0) to connect to the 8255A