Compatibility: EMS 4.0+
Expects: AH    54H
AL    subfn: 00H=Query handle directory
ES:DI addr buffer to receive data
01H=Search for named handle
DS:SI addr of 8-byte buffer containing name
02H=Count all open handles
                                                                  
Returns: AH    EMM status (0=successful)
ES:DI (fn 5400H) contains returned data (see below)
DX    (fn 5401H) handle with specified name
BX    (fn 5402H) count of handles; use a buffer size of BX*10
                                                                  
Info: This lets applications work together, sharing EMS pages, as long
as each app knows an 8-character name.

ES:DI (fn 5400H) returns with this buffer filled with EMS handle names.
It is formatted as:

EmsHandleNameRec
Offset Size Contents
                                                          
+0      2  wHandle   an EMM handle
+2      8  abName    8-bytes of the name
10            size of one EmsHandleNameRec
+0aH     2  wHandle2
+0cH     8  abName
.
:
etc.

Before using fn 5400, use fn 5402H to see how large the buffer
should be.

Notes: Names can be any 8 byte.  When a handle has a name of all 0s, it
is considered to be unnamed.  See INT 67H 53xxH (get/set name).

- -

INT 67H 54xxH: Find Named Handle