The expand connector is directly mapped to the 28- and 40-pin DIP sockets. Pin 1 on the connector - is pin one on both the 28 and the 40pin DIP socket. When doing either programming or debugging on-board, the appropriate signals should be routed from the SPI(ISP), JTAG, VCC, and HV_PROG headers to the correct pins on the EXPAND connector. Read the Using the Atmel AVR Dragon Prototype Area section for more information on how to use this function.