Int 31 Fn 0500  P - DPMI 0.9+ - Get Free Memory Information                [E]

   AX = 0500h
   ES:(E)DI -> buffer for memory information (see below)

Return: CF clear

Notes: 16-bit programs use ES:DI, 32-bit programs use ES:EDI
   this function must be considered advisory because other applications
     may affect the results at any time after the call
   fields not supported by the DPMI implementation are filled with
     FFFFFFFFh
   DPMI 1.0+ supports this function solely for backward compatibility; use
     AX=050Bh instead
   the limited DPMI host built into Phar Lap's 286|DOS-Extender v2.5 only
     returns the first field in the memory information record

See Also: AX=0501h,AX=0604h

Format of memory information:
Offset Size    Description
 00h   DWORD   largest available block in bytes
 04h   DWORD   maximum unlocked page allocation
 08h   DWORD   maximum locked page allocation
 0Ch   DWORD   total linear address space in pages
 10h   DWORD   total unlocked pages
 14h   DWORD   free pages
 18h   DWORD   total physical pages
 1Ch   DWORD   free linear address space in pages
 20h   DWORD   size of paging file/partition in pages
 24h 12 BYTEs  reserved