The driver is generic, to cover serial and parallel ports. The EggBot itself requires USB, and is not set up for use with a parallel port.
There are many projects that do use the parallel port for controlling stepper motors. The port is certainly capable of providing the drive signals, but it does not provide enough current for the motor coils, so you would need some kind of external power driver between the port and the motor.
There are no port pins, so there is no description. The EggBot software is written to control a specific device, that does not have a parallel interface.