SECTION 6
Conversions and Interfaces
6-114 PEN*KEY
R
6200/6300 Hand-Held Computer Programmer’s Reference Guide
INT 1Ah, Function AH = 02h: Read the Real-Time Clock Time
BIOS
Reads the hour, minute, second, and Daylight Savings option data from the
CMOS RAM area of the MC 146818. Must verify that the updateĆinĆprogress bit
is zero and disable interrupts before accessing the CMOS data.
On Entry:
AH =02h
On Return:
If successful:
Carry = 0
CH = Hours in BCD (0ć23)
CL = Minutes in BCD (0ć59)
DH = Seconds in BCD (0ć59)
DL = Daylight Savings Time option
0 No Daylight Savings Time
1 Daylight Savings Time
If NOT successful:
Carry = 1
INT 1Ah, Function AH = 03h: Set Real-Time Clock Time
BIOS
Writes the hour, minute, second, and Daylight Savings option data to the CMOS
RAM area of the MC 146818. This function must wait for the updateĆinĆprogress
bit to become zero and disable interrupts before accessing the CMOS data.
On Entry:
AH = 03h
CH = Hours in BCD (0ć23)
CL = Minutes in BCD (0ć59)
DH = Seconds in BCD (0ć59)
DL = Daylight Savings Time option
0 No Daylight Savings Time
1 Daylight Savings Time
On Return:
If successful:
Carry = 0
If NOT successful:
Carry = 1
6. Conversions and
Interfaces
