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)