Format:	/UNIT=n

 This qualifier will attempt to create a client device with the unit
 number specified.  For disk client devices the format of the client
 device is _DADn: and for tape client devices the format is _MADn:.  If
 the unit specified already exists an error is returned.  The default
 behaviour is to assign a unit number starting at 1 and increasing by 1
 each time a unit is created.  Valid unit numbers are positive integers
 in the range of 1 thru 32767.

 examples:

 LADCP> bind/unit=354 fred
 %LADCP-I-BIND, service bound to logical unit DAD$FRED (_DAD354:)

 LADCP> bind/unit=4 harry
 %LADCP-E-UNITEXISTS, device _DAD4: exists