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AND STUDIO RECORDING: A MIDI command consists of a number of bytes (combinations of 8 bits), each of which is preceded by a start bit (a 0) and followed by a stop bit (a 1). The first byte in a message is always a status byte which defines the type of command (e.g. note on, patch change, pitch bend etc), and this is then followed by one or more data bytes, which qualify and quantify the message. MIDI can recognise a data or status byte from its first bit (excluding the start bit) of the first nibble: if it is a 0 (i.e. nibble = 0-127 inclusive) then the byte is a data byte; if it is a 1 (i.e. nibble = 128-255 inclusive) then the byte is a statusbyte. The
MIDI Specification 1.0 gives the exact meaning of all defined status
bytes, and gives the number of data bytes which must follow each
status byte. Their values and meanings are also strictly defined. |