IBM Personal System/2 65 SX - Real-Time-Clock Bytes

Real-Time-Clock
Bytes
(Hex
000-00D)
Bit
definitions
and
addresses
for
the
real-time-clock
bytes
are
shown
in
the
following
table.
Address
Byte
(Hex)
Function
Number
000
Seconds
0
001
Second
Alarm
1
002
Minutes
2
003
Minute
Alarm
3
004
Hours
4
005
Hour
Alarm
5
006
Day
of
Week
6
007
Date
of
Month
7
008
Month
8
009
Year
9
00A
Status
Register
A
10
00B
Status
Register
B
11
00c
Status
Register
C
12
00D
Status
Register
D
13
Figure
3-10.
Real-Time
Clock Bytes
Note:
The
Setup
program
initializes
Status
Registers
A,
B,
C,
and
D
when
the
time
and
date
are
set.
Interrupt
hex
1A
is
the
BIOS
interface
to
read
and
set
the
time
and
date,
and
it
initializes
the
register
the
same
way
as
the
Setup
program.
3-14
Model
65
System
Board
—
October
1990