The LDDRIVER understands all functioncodes normally available
 	for disks. Some special functions are used to control the
 	logical disk driver. When loaded as a tape (LMax) it will
 	understand tape functioncodes.

 	All functions assume that a channel has been assigned to
 	the device on which to operate. One exception is the 'Connect'
 	function which needs a channel to LDA0:. This will then create
 	a new device (because LDA0: is a cloned device).

 	A file with LDdriver specific definitions is included in the
 	kit (LDDEF.H). This file will be included in VMS from version
 	V8.2-1 and up.

 	The only function to control the driver is IO$_LD_CONTROL
 	which is defined in LDDEF.H.
 	A sub-function must be given as P6 of the QIO request.