Int 21 Fn 252E  P - Phar Lap 386/dos-extender Vmm V2.3+ - Get/set Vmm Par  [E]

   AX = 252Eh
   CL = direction (00h get parameters, 01h set parameters)
   DS:EBX -> parameter buffer (see below)

Return: CF clear if successful
   CF set on error
       EAX = error code (81h bad parameter value)

Format of VMM parameter buffer:
Offset Size    Description
 00h   DWORD   flags
       bit 0: page fault logging enabled
       ---v5.0+ ---
       bit 1: swap extender to disk during DOS EXEC call
       bit 2: don't zero allocated memory
 04h   DWORD   scan period for page aging, in milliseconds
 08h   DWORD   maximum size (in bytes) to check on each page scan
 0Ch 52 BYTEs  unused