[fowlerm]

I found that pins 1-3 are Tx1, Rx1, and Gnd, respectively, for UART 1 on the user uP. The only major difference between the Vex controller's serial port and that of the Edu controller is that there is no onboard TTL - RS232 converter. All I did to build a module is convert the TTL signals to RS232 signals with a MAX232 chip from TI and then use IFI Loader to communicate with the Vex controller. The other pins on the Vex's serial port are control lines RTS and CTS, and the actual line that puts the controller in program state (similar to what the program button does for the other IFI controllers. I used a 25' 6-conductor telethone cable from RadioShack (part #279-422) and then put a button on the module that will put the controller in program state.