[SpookyZalost]

actually... quite a lot, you can run it as 9 bi-directional serial connections if you want at 1.5mbps per lane with 8 bit data transfer.

I know that doesn't seem like a lot but parallel EEPROM programmers are still some of the fastest out there as far as time to flash the EEPROM chips vs maybe dedicated rigs and Lan based setups.

you can go up to 12 bi-directional connections with a single ground wire as well if you really wanted to push it but that takes a lot of custom work... and that's if you're doing a parallel to parallel Null Modem connection.