INT 2F - KS/KEYSTKCT.EXE - INSTALLATION CHECK                                   
	AX = FD12h
Return: AX = 0093h if installed
	    ES = resident code segment
	    ES:CX -> internal "putbuf" routine
Program: KS/KEYSTKCT.EXE is a key stacking utility (4DOS KEYSTACK.SYS
	  look-alike) by Martin Gerdes, published in c't 11/1991, which can be
	  loaded as a device driver or as a TSR(Terminate and Stay Resident) A program which remains in memory after terminating in order to provide services to other programs or the user.  The name comes from the name of the DOS function call used to remain in memory after termination.. It does not emulate 4DOS
	  KSTACK 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.
Note:	the default buffer size is 128 keys