Int 21 Fn 4402  U - Memory Managers - Get API Entry Point                  [m]

   AX = 4402h subfn 00h
   BX = file handle for device "EMMXXXX0"
   CX = 0006h (size of buffer in bytes)
   DS:DX -> buffer for API entry point record (see below)
       first byte must be 00h on entry

Return: CF clear if successful
       buffer filled (see INT 67/AH=3Fh function 1B00h)
   CF set on error
       AX = error code (01h,05h,06h,0Dh) (see AH=59h)

Notes: this function is supported by Microsoft EMM386.EXE v4.45+ and
     CEMM v5.10+, and is intended for use by MS Windows as it starts up
   if no other program has hooked INT 67, an alternate installation
     check for CEMM is testing for the string
     "COMPAQ EXPANDED MEMORY MANAGER 386" at offset 14h in the INT 67
     handler's segment; if present, the word at offset 12h contains the
     offset of the API entry point

See Also: AX=4402h/SF=01h,AX=4402h/SF=02h,AX=4402h"EMM386",INT 67/AH=3Fh

Format of API entry point record:
Offset Size    Description
 00h   WORD    ??? (0022h for CEMM 5.11, 0025h for MS EMM386 v4.45)
 02h   DWORD   manager's private API entry point (see below,INT 67/AX=FFA5h)

Call CEMM v5.10+ entry point with:
   AH = 00h get memory manager's state

       Return: AH = state
           bit 0: turned OFF
           bit 1: AUTO mode enabled
   AH = 01h set memory manager's state
       AL = new state (00h ON, 01h OFF, 02h AUTO)

       Return: CF clear if successful
           CF set on error
   AH = 02h Weitek coprocessor support
       AL = subfunction
       00h get Weitek support state

           Return: AL = status
               bit 0: Weitek coprocessor is present
               bit 1: Weitek support is enabled
       01h turn on Weitek support
       02h turn off Weitek support

       Return: CF clear if successful
           CF set on error
           AH = error code (01h invalid subfunc, 02h no Weitek)
   AH = 05h get statistics
       ???
   AH > 06h

       Return: CF set
           AH = 01h (invalid function)

Notes: AH=03h,04h,06h are NOPs which return CF clear, presumably for backwards
     compatibility with earlier versions of CEMM
   in v5.11, AH=05h merely prints an error message (using INT 21/AH=09h)
     stating that a different version of CEMM is installed and it is
     therefore not possible to display the statistics