NAME
	TD_GETDRIVETYPE -- return the type of disk drive for the unit that was
			   opened.

   FUNCTION
	This command returns the type of the disk drive to the user.
	This number will be a small integer and will come from the set of
	DRIVEXXX constants defined in <devices/trackdisk.h>.

	The only way you can actually use this command is if the trackdisk
	device understands the drive type of the hardware that is plugged in.
	This is because the OpenDevice() call will fail if the trackdisk device
	does not understand the drive type. To find raw drive identifiers see
	the disk.resource's DR_GETUNITID entry point.

   IO REQUEST INPUT
	io_Device	preset by the call to OpenDevice()
	io_Unit		preset by the call to OpenDevice()
	io_Command	TD_GETDRIVETYPE
	io_Flags	0 or IOF_QUICK

   IO REQUEST RESULT
	io_Error - 0 for success, or an error code as defined in
	           <devices/trackdisk.h>
	io_Actual - if io_Error is 0 this contains the drive type connected to
		    this unit.

   SEE ALSO
	TD_GETNUMTRACKS, <devices/trackdisk.h>