INT 62 U - GWBTSR - 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 = C0h AL = function 00h installation check Return: AX = 00FFh if installed 01h ??? Program: GWBTSR is a huge (48K) resident mixer controller for the Gateway 2000 sound card (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor. version of Aztech Sound Galaxy) Index: installation check;GWBTSR