## MMPM/2 Device Driver Reference

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### Timing Compression Messages

These messages are used to compress sequential timing clocks (F8) into a single system exclusive message. Up to 16383 (that is, F8 Timing clocks can be compressed into a single 6- or 8-byte message, which can be written to a device driver to cause a delay between output events if output synchronizing is enabled (see Device Driver Control Messages).

     F0  00 00 3A  01  ll  mm  F7  (Long version)

     F0  00 00 3A  nn  F7          (Short version)

     ll = Number of System Real Time Timing Clocks LSB

     mm = Number of System Real Time Timing Clocks MSB

     nn = Number of System Real Time Timing Clocks (nn = 7 through 127)

The short version can be used to represent durations of from 7 - 127 clocks . Longer durations can be represented with the long version, where the number of timing clocks that have occurred is calculated by combining the low 7-bits of mm with the low 7-bits of ll to produce a single 16-bit value :

       0mmm mmmm + 0lll llll = 00mm mmmm mlll llll