SECTION 6
Conversions and Interfaces
PEN*KEY
R
6200/6300 Hand-Held Computer Programmer’s Reference Guide 6-115
INT 1Ah, Function AH = 04h: Read Real-Time Clock Date
BIOS
Reads the century, year, month, and day from 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 = 04h
On Return:
If successful:
Carry = 0
CH = Century in BCD (19 or 20)
CL = Year in BCD (0ć99)
DH = Month in BCD (1ć12)
DL = Day in BCD (1ć31)
If NOT successful:
Carry = 1
INT 1Ah, Function AH = 05h: Set Real-Time Clock Date
BIOS
Writes the century, year, month, and day data to the CMOS data 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 = 05h
CH = Century in BCD (19 or 20)
CL = Year in BCD (0ć99)
DH = Month in BCD (1ć12)
DL = Day in BCD (1ć31)
On Return:
If successful:
Carry = 0
If NOT successful:
Carry = 1
6. Conversions and
Interfaces
