5.7 MAGIC

MAGIC ¹⁰ (Media-accelerated Global Information Carrier) was developed by the Gibson Guitar Corporation, originally going under the name GMICS. It is a relatively recent audio interface that typically uses the Ethernet physical layer for transporting audio between devices, although it is not compatible with higher layers and does not appear to be interoperable with conventional Ethernet data networks. It uses its own application and data link layers , the data link layer of which is based on the Ethernet 802.3 data link layer, using a frame header that would be recognized by 802.3-compatible devices.

Although it is not limited to doing so, the described implementation uses 100Mbit/s Fast Ethernet over standard CAT 5 cables, using four of the wires in a conventional Ethernet crossover implementation and the other four for power to devices capable of operating on limited power (9 volt, 500mA). Data is formed into frames of 55 bytes, including relevant headers, and transmitted at a synchronous rate between devices. The frame rate is related to the audio sampling rate and a sampling clock can be recovered from the interface. Very low latency of 1040 s is claimed. MAGIC data can be daisy-chained between devices in a form more akin to point-to-point audio interfacing than computer networking, although routing and switching configurations are also possible using routing or switching hubs.