INT 68 - APPC/PCIBM PC - ENABLE/DISABLE 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. VERB TRACING
	AH = FDh
	AL = new tracing state (00h disabled, 01h enabled)
SeeAlso: AH=FAh,AH=FCh,AH=FEh