Int 31 Fn 0504  P - DPMI 1.0+ - Allocate Linear Memory Block               [E]

   AX = 0504h
   EBX = page-aligned linear address of memory block (00000000h if any
       address is acceptable)
   ECX = size in bytes (nonzero)
   EDX = flags
       bit 0: set to create committed pages instead of uncommitted pages
       bits 1-31 reserved (0)

Return: CF clear if successful
       EBX = linear address of memory block
       ESI = memory block handle
   CF set on error
       AX = error code (8001h,8012h-8014h,8016h,8021h,8025h)(see AX=0000h)

Note:  only supported by 32-bit DPMI hosts, but may be used by 16-bit clients

See Also: AX=0501h,AX=0505h