Note: This API call is for DOS personality only. Use Family API for portability.
Int 21H, AH=55H
2 and higher
CREATE CHILD PSP
AH = 55h DX = segment at which to create new PSP SI = (DOS 3.0+) value to place in memory size field at DX:[0002h]
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 2.0+) sets current PSP to DX (DOS 3.0+) marks "no inherit" file handles as closed in child PSP this function is implemented using the same code as AH=26h, so unlike other DOS 2+ functions, it does not return status in CF, instead returning status in AL as DOS 1.x functions do (but it never puts an explicit return value in AL)
Text based on Ralf Brown Interrupt List Release 61