Int 31 Fn FF28  P - Causeway V1.3 - "setmcbsize" - Set Mcb Memory Allocat  [E]

   AX = FF28h
   ECX = new threshold (0000000h to disable MCB memory allocation system)

Return: CF clear if successful
       threshold unchanged (default 16K)
   CF set on error (threshold > 64K)
Desc:  specify the memory allocation size below which CauseWay will use
     internal MCB chains rather than allocating full 4K pages via DPMI

Note:  the specified threshold will be rounded up to the next higher multiple
     of 4K

See Also: AX=FF00h,AX=FF27h