Int 21 Fn 55  - DOS 2+ Internal - Create Child Psp                         [D]

   AH = 55h
   DX = segment at which to create new PSP
   SI = (DOS 3+) value to place in memory size field at DX:[0002h]

Return: CF clear if successful


Notes: creates a "child" PSP rather than making an exact copy of the current
     PSP; the new PSP's parent pointer is set to the current PSP and the
     reference count for each inherited file is incremented
   (DOS 2+) sets current PSP to DX
   (DOS 3+) marks "no inherit" file handles as closed in child PSP

See Also: AH=26h,AH=50h