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A Musical Instrument Digital Interface (MIDI) cable uses a standardized 5-pin DIN connector. The pin configuration will depend on whether the connector is being used in to a MIDI In, MIDI Thru, or MIDI Out configuration.
The pins for a MIDI In configuration are as follows: Pin 1, not connected; Pin 2, not connected; Pin 3, not connected; Pin 4, IN+; Pin 5, IN-. Configurations for MIDI Through use are: Pin 1, not connected; Pin 2, Shield; Pin 3, not connected; Pin 4, +5v; Pin 5, IN. Configuration for a MIDI Out port is the same as for a Midi Thru port.
Please note that the pin configuration for all MIDI connectors only use the three middle pins on a standard 5-pin DIN connector; the outer pins are not used. - The maximum length for a MIDI cable is 50 feet. Although there are a number of types of cable that will work, cables with braided shielding are best for applications where the cable must flex. Cables with foil shielding are best for permanent installations or where the cable won't flex much. Microphone cable usually makes a very good MIDI cable.
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MIDI cables transmit data in a serial, or sequential, format. Data is sent in a digital sequence over Pins 4 and 5 of the DIN connector. MIDI files are divided into chunks. The header chunk contains overall data about the music to follow. This includes format type, time division data, and the number of tracks to follow. Each MIDI file contains only one header chunk.
Each track transmitted over a MIDI cable contains a track chunk. The track chunk data could include a wide range of data, depending on the musical contents of the track. All track chunks contain a chunk ID and define a chunk size for the data to follow. Track event data follows the chunk ID and the chunk size.
Each musical note is defined in a MIDI channel event. MIDI channel events contain data on note duration, velocity of the key that played the note, if the pitch bends, and information on the controller on which the note was played.
Controller events and controller types often differ depending on the capabilities of the controller used to control the synthesizer.
