LeapFrog Pollux Platform: Hardwire Serial Connection
After some probing, I found the serial console (115200 8N1) comes out to the cartridge connector. Counting from the right, tx comes out on pin 12 and rx on pin 11. The voltage level goes between 0 and 3.3 volts. Hooking into a TTL to RS-232 converter, left over from another project, I can get to the console.
Picture from Claude Schwarz’s BLOG