Digital Control Bus: Difference between revisions

Revision as of 01:20, 27 September 2011

Revision as of 01:27, 27 September 2011

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=== Message (Block) Structure) ===

DCB data is sent in short blocks messages consisting of an identifier, one or more data codes, and an end mark. Blocks may be sent intermittently (JP-8, OP-8) or continuously (Juno 60), in which case end marks are not used.

The DCB is a standard asynchronous serial stream (using an 8251A IC in the Juno 60), LSB first, 8 data bits, 2 stop bits, odd parity, and a Baud rate of 31.25kHz. It is sent in short blocks messages consisting of an identifier, one or more data codes, and an end mark.

{| class="wikitable"

Blocks may be sent intermittently (JP-8, OP-8) or continuously (Juno 60), in which case end marks are not used.

|-

! Identifier/start !! Data !! Data !! ... !! End

|-

| F1-FE || 0-F0 || 0-F0 || ... || FF

|}

Identifier is 1 byte using a value F1 through FE, which acts as both a start marker and a message type. Data which follows must not use these data bytes. In practice only FD (patch code) and FE (key code) are used.