INT 15,C3 - Enable/Disable Watchdog Timer (PS/2)
AH = C3 AL = 0 disable watchdog time-out = 1 enable watchdog time-out BX = watchdog timer count (1-255) on return: CF = 0 if successful = 1 if error AH = when CF set, 80h for PC & PCjr, 86h for XT, AT & Model 30 - the watchdog timer is available only on PS/2 with 80286 and 80386 processors. - the timer uses channel timer channel 3 and IRQ0. Activated when IRQ0 is active for more than one channel 0 timer cycle, which causes the timer to be decremented. When the watch- dog timer reaches 0, and NMI is generated.