INT 67H 52xxH: Get/Set Handle Attribute

                                                     Compatibility: EMS 4.0+ 
 Expects: AH    52H
          AL    subfn: 00H=Query handle attribute
                       01H=Set handle attribute
                       12H-Query capability
          DX    EMM Handle (as obtained via INT 67H 4300H)
 Returns: AH    EMM status (0=successful)
          AL    (fn 5200H) attribute: 00H = volatile
                                      01H = non-volatile (lives thru reboot)
                (fn 5202H)   support: 00H = NO support for non-volatile pgs
                                      01H = OK to tag as non-volatile
    Info: EMS 4.0 describes this system in which you can mark the pages of
          a handle as "volatile" and "non-volatile".  Pages of a
          non-volatile handle will be intact after a warm boot.

          Most EMS cards and EMM emulators do not support this capability,
          so don't waste your time or mine.

See Also: INT 67H: EMM Services
          Extended Memory Specification (XMS)
          Interrupts and BIOS Services