3-11. Real-Time Clock Bytes - IBM Personal System/2 50 Technical Reference

Real-Time Clock Bytes (Hex OOO-OOD)
Bit definitions and addresses for the real-time clock bytes are shown
in the following figure.
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
OOA Status Register A
10
008 Status Register 8 11
OOC Status Register C 12
000 Status Register 0
13
Figure
3-11. 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.
Model 50 System Board 3-15