The AR488 GPIB controller is an Arduino-based controller for interfacing with IEEE488 GPIB devices via USB. This work was inspired by and has been based on the work originally released by Emanuele ...

But the key benefit is that different pins can handle the same purpose. For audio the Greater Than Zero Pis (GTZPi) use PWM0_OUT and PWM1_OUT on the processor’s GPIO pins 40 and 45.

It’s a significant update. The Arduino UNO and Arduino Mega 2560 update the Duemilanove and Mega respectively. They now use an ATMega8U2 instead of an FTDI USB to serial converter chip.