INT 11 - RainbowFAX v1.3 - SFENGINE 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. - ??? AH = 78h AL = subfunction 01h set ??? BX = new state for ??? 0000h ??? else ??? Return: AX = 0001h 02h set ??? BX = ??? CX = ??? Return: AX = 0001h 03h set ??? BX = new state for ??? 0000h ??? else ??? Return: AX = 0001h else Return: AX = FFFFh (invalid subfunction) SeeAlso: AH=77h,AH=79h,AH=7Ah,AH=7Ch