| 摘要 |
A keyboard assignment system for a polyphonic electronic musical instrument employs a small number (typically ten or twelve) of output channels each capable of storing a note identification code used to control generation of a corresponding tone. Output channels are assigned and/or released during an assignment cycle initiated when any keyboard key is depressed or released. During the assignment cycle a keyboard switch matrix and an encoding matrix cooperate to provide sequentially on a data buss note identification codes corresponding to depressed keys. The data buss is connected to all output channels. An identity signal is produced by each output channel which is storing a note identification code corresponding to any which appears on the data buss during the assignment cycle. Assignment logic, responsive to these identity signals, assigns an output channel to each newly depressed key on a priority basis, and releases each output channel which had been assigned to a key which is now released.
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