Library /sys$common/syshlp/ess$lastcphelp.hlb START TRANSPORT, /CONTROLLERS, unit-names  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 A unit name is of the form DDCU: where

   DD is the device type
    C is the controller field
    U is the unit number

 When specifying controllers for LASTDRIVER use the controller field of
 the unit name.

 XQA0 is controller A
 XEB0 is controller B