INT 21 - OS/2 v1.1+ Family API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. - DosSetPathInfo AX = 5703h BX = FFFFh CX = size of information buffer DX = level of information DS:SI -> filename ES:DI -> information buffer Return: CF clear if successful CF set on error AX = error code SeeAlso: AX=5702h/BX=FFFFh,AX=5703h"OS/2"