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Function 22 - set the system date / time

Options:

  * eax = 22 - function number

  * ebx = 0 - set the time

    * ecx = 0x00SSMMHH - time in binary coded decimal code (BCD):

    * HH = hour 00..23

    * MM = minute 00..59

    * SS = second 00..59

  * ebx = 1 - set the date

    * ecx = 0x00DDMMYY - the date in the binary decimal code (BCD):

    * DD = day 01..31

    * MM = month 01..12

    * YY = year 00..99

  * ebx = 2 - set the day of the week

    * ecx = 1 for sunday, ..., 7 for saturday

  * ebx = 3 - set the alarm

    * ecx = 0x00SSMMHH

Return value:

  * eax = 0 - successful

  * eax = 1 - the parameter is set incorrectly

  * eax = 2 - CMOS-batteries are out

Remarks:

  The value of the installation of the day of the week seems doubtful, since it is not used very much (the day of the week can be calculated by date).

  The alarm can be set to operate at a specified time every day. At the same time, it cannot be disabled by the existing system functions.

  The alarm is triggered by the generation of IRQ8.

  In fact, CMOS supports setting the value 0xFF as one of the parameters for an alarm and means that the corresponding parameter is ignored. But in the current implementation it will not work (return value 1).

  Alarm clock is a global system resource; setting the alarm automatically cancels the previous setting. However, at the moment no program uses it.

Constants for registers:

eax - SF_SET_TIME_DATE (22)