Int 2F Fn 4A01  - Dos 5+ - Query Free Hma Space                            [D]

   AX = 4A01h

Return: BX = number of bytes available in HMA (0000h if DOS not using HMA)
   ES:DI -> start of available HMA area (FFFFh:FFFFh if not using HMA)

Notes: called by Windows 3.1 DOSX.EXE
   supported by Novell DOS 7

See Also: AX=4310h,AX=4A02h