## MMPM/2 Device Driver Reference

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### Device Driver Response Messages

The following are types of device driver response messages:

Device capability
Device ID
Queue size

Device Capability Response

This message is sent by a device driver in response to a query device capability message (see Device Driver Query Messages). It indicates the basic MIDI capability of the device driver.

      F0 00 00 3A  05  01  ii mm 00 F7

      ii = Number of sound generators (instruments)

      mm = MIDI capability flags

           01xx xxxx MIDI input is supported

           0x1x xxxx MIDI output is supported

           0xx1 xxxx System real-time Timing clocks are supported

Device ID Response

This message identifies the device and is sent by a device driver in response to a query device ID message (see Device Driver Query Messages).

      F0 00 00 3A  05  04  b1 b2 b3 F7

      b1 = 1st byte of Device ID

      b2 = 2nd byte of Device ID

      b3 = 3rd byte of Device ID

This message is provided to permit applications to perform device unique operations such as issuing device-specific system exclusive messages.

Queue Size Response

This message is sent by a device driver in response to a query output queue size message (see Device Driver Query Messages). It indicates the total output queue size in bytes.

      F0 00 00 3A  05  02  ll mm 00 F7

      ll = Lower 7 bits of queue size

      mm = Upper 7 bits of queue size

      (Queue Size in bytes = 00mm mmmm mlll llll)

For example, if the device driver's output queue is 512 bytes in length, the returned data is:

       F0 00 00 3A  05  02  00  04  00  F7