INT 1A - System and Real Time Clock BIOS Services

	For more informations, see the following topics:

	INT 1A,0   Read system clock counter
	INT 1A,1   Set system clock counter
	INT 1A,2   Read real time clock time (AT,PS/2)
	INT 1A,3   Set real time clock time (AT,PS/2)
	INT 1A,4   Read real time clock date (AT,PS/2)
	INT 1A,5   Set real time clock date (AT,PS/2)
	INT 1A,6   Set real time clock alarm (AT,PS/2)
	INT 1A,7   Reset real time clock alarm (PS/2)
	INT 1A,8   Set RTC activated power on mode (convertible,PS/2)
	INT 1A,9   Read RTC alarm time and status (convertible,PS/2)
	INT 1A,A   Read system day counter (PS/2)
	INT 1A,B   Set system day counter (PS/2)
	INT 1A,80  Set up sound multiplexer (PCjr only)

	- function is specified in register AH
	- see	RTC