1. All leads P0 P1 P2 P3 interface pin header, P0 pull-up resistor.

2. There is 5V power connector, pin and DC5

3. There are power indicator

4.12MHz crystal oscillator

5. The convenient interface RXD TXD GND STC microcontroller serial download.

6. There ATMEL ISP download port for easy AT89S series microcontroller downloaded.

7. There are self-locking power switch

8. There reset button

9. locking seat for easy replacement chip

10. APCB size 40mm X 88mm

11. There are four positioning mounting screw holes