Int 67 Fn FFA5  - Microsoft Emm386.exe V4.20+ - Installation Check         [m]

   AX = FFA5h

Return: AX = 845Ah/84A5h if loaded
       BX:CX -> API entry point (see #3337)

Notes: this call is available even if EMM386 is not providing EMS
   the returned AX is 845Ah inside of MSWindows, 84A5h under bare DOS
   if no other program has hooked INT 67, an alternate installation
     check is to test for the string
     "MICROSOFT EXPANDED MEMORY MANAGER 386" at offset 14h in the INT 67
     handler's segment; the word immediately preceding this string
     contains the offset of the API entry point

See Also: AH=3Fh,AX=FFA5h/BX=4345h,INT 21/AX=4402h"EMM386.EXE"

(Table 3337)
Call EMM386.EXE API entry point with:
   AH = 00h get memory manager's status

       Return: AH = status
           bit 0: not active (OFF)
           bit 1: in "Auto" mode
   AH = 01h set memory manager's state
       AL = new state (00h ON, 01h OFF, 02h AUTO)
   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
     --- v4.20-4.41 only ---
   AH = 03h Windows support???
       AL = subfunction (00h, 01h)
   AH = 04h print copyright notice to standard output
        (using INT 21/AH=09h)
   AH = 05h print available report
        (the one shown when running EMM386 from the DOS prompt)

See Also: #1200 at INT 21/AX=4402h/SF=02h,#2304 at INT 2F/AX=12FFh/BX=0106h