[Alan Anderson]

The Competition Port Pinout Guide shows connections to pins 5, 6, 8, and 12 only. It says, in large bold UPPERCASE letters:

CONNECTIONS TO ANY OTHER PINS CAN DAMAGE THE OI AND WILL VOID ANY WARRANTY

Note that for the 2005 OI, grounding pin 12 to enable the alternate radio modem channels is unnecessary (but the alternate channels will only work if the team number is set to 2048 or higher).