INT 70h (112)            Real-Time Clock              XT-286, AT, Convertible

Handles the alarm and periodic interrupts for the real-time clock.


This is a hardware interrupt (IRQ 8) activated by the CMOS timer 1024
times per second.

Notes:         This interrupt is available only on the AT and XT-
286. The real-time clock on the PC Convertible
generates an INT 02h (Non-Maskable Interrupt) to
handle the periodic and alarm functions.

This interrupt provides two services. The first is
the periodic interrupt that is generated when a time
delay is specified. See INT 15h, Service 83h (Event
Wait), and Service 86h (Wait), for more information.
The second service is the Alarm Interrupt. When the
CMOS alarm time matches the current CMOS time, then
INT 4Ah (User Alarm) is executed.

See also: INT 15h, 83h
See also: INT 15h, 86h
See also: INT 4Ah
See also: INT 1Ah, 06h

INT 70h (112) Real-Time Clock