The MIDI Translator II interface attaches to either the modem or printer port on the Macintosh. It provides one MIDI In and three MIDI Outs that may be connected to any synthesizer, drum machine, or other MIDI device using standard MIDI cables. It includes a thru switch for the serial port connection and MIDI IN/OUT activity indicator LEDS. The MIDI Translator II requires no power supply. Serial Cable included free.