INT 1Ah, 09h (9) Read Clock Alarm Time and Status Convertible
Reads the alarm time and status from the real-time clock.
On entry: AH 09h
Returns: CF Set if clock operating; else cleared
CH Hours (BCD)
CL Minutes (BCD)
DH Seconds (BCD)
DL Alarm Status
00h - Alarm not enabled
01h - Alarm enabled but will not power-on
system
02h - Alarm enabled and will power-on
system
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Notes: Note that all dates are in Binary Coded Decimal
(BCD). For example, June 1, 1985 will be set as CX =
1985; DX = 0601.
The real-time clock is the clock that runs even when
the computer is turned off. A CMOS battery is used
so that, even while the computer is off, the date,
time, and alarm time are maintained.
This service is available only for the PC
Convertible. ATs and XT-286s will set the Carry
Flag, thus reporting an error state. Previous
machines will report unpredictable results
(including the state of the Carry Flag).
Seealso:
This page last updated on Fri Nov 30 10:49:50 MSK 2001
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