IBM PC CONVERTIBLE

5. PURPOSE OF ENTRY: READ DATE FROM REAL TIME CLOCK
INPUT CONDITIONS: AH = 04H
NORMAL EXIT CONDITIONS: CH = CENTURY IN BCD (19H OR 20H)
Cl = YEAR IN BCD
DH = MONTH IN BCD
Dl = DAY OF MONTH IN BCD
ERROR EXIT CONDITIONS: CF FLAG SET IF ClK NOT OPERATING
REGISTERS MODIFIED: AX, CX, OX
6. PURPOSE OF ENTRY: SET DATE OF REAL TIME CLOCK
INPUT CONDITIONS: AH = 05H
CH = CENTURY IN BCD (19H OR 20H)
Cl = YEAR IN BCD
DH = MONTH I N BCD
Dl = DAY OF MONTH IN BCD
REGISTERS MODIFIED: AX
7. PURPOSE OF ENTRY: SET ALARM TIME OF REAL TIME CLOCK
INPUT CONDITIONS: AH = 06H
CH = HOURS I N BCD
Cl = MINUTES IN BCD
DH = SECONDS I N BCD
NORMAL EXIT CONDITIONS: CF FLAG = 0
ERROR EXIT CONDITIONS: CF FLAG SET IF ClK NOT OPERATING
CF FLAG SET I F ALARM ALREADY ENABLED
RESTRICTIONS: THE USER MUST CODE A RTN AND PUT
CORRECT ADDRESS IN THE VECTOR TABLE
FOR INT 4AH.
REGISTERS MODIFIED: AX
8. PURPOSE OF ENTRY: RESET THE ALARM
INPUT CONDITIONS: AH = 07H
NORMAL EXIT CONDITIONS: NONE
ERROR EXIT CONDITIONS: NONE
REGISTERS MODIFIED: AX
9. PURPOSE OF ENTRY: SET ALARM TIME OF RTC FOR POWER ON
INPUT CONDITIONS: AH = 08H
CH = HOURS IN BCD
Cl = MINUTES IN BCD
DH = SECONDS I N BCD
NORMAL EXIT CONDITIONS: CF FLAG = 0
ERROR EXIT CONDITIONS: CF FLAG SET IF ClK NOT OPERATING
CF FLAG SET I F ALARM ALREADY ENABLED
REGISTERS MODIFIED: AX
10. PURPOSE OF ENTRY: READ ALARM TIME OF RTC AND STATUS
INPUT CONDITIONS: AH = 09H
NORMAL EXIT CONDITIONS:
CH = HOURS I N BCD
Cl = MINUTES IN BCD
DH = SECONDS IN BCD
Dl = ALARM STATUS
00 - ALARM NOT ENABLED (AI E=O)
01 - ALARM ENABLED BUT Will NOT POWER
ON SYSTEM (AIE=l, EN_PON-'llRM=O)
02 - ALARM ENABLED AND WILL POWER ON
SYSTEM (AIE=l, EN_PON_AlRM=l)
ERROR EXIT CONDITIONS: CF FLAG SET IF CLK NOT OPERATING
REGISTERS MODIFIED: AX, CX, OX
NOTE: FUNCTION CALLS WITH AH NOT EQUAL TO THE
ABOVE RESULT IN NO OPERATION
WITH THE CARRY FLAGE BEING CLEARED
INTERRUPTS: FUNCTIONS 0, 1 FORCED OFF (CLI)
FUNCTIONS 2 - 9 FORCED ON (STI)
ON EXIT RESTORED AS WERE
ROM BIOS 2-155