Does anybody know how to use the alarm bytes in CMOS?

I'v tryed the Assembler messageboard, but nobody answerd. So, now I'm asking you.



How do I use them?

Do they activate any interrupt?

What interrupt?


Comments

  • The CMOS alarm register can be used to set an alarm for the same day since there is only hour, minute and second values available. To use the CMOS alarm, load the alarm value in the appropriate ram addresses. When the alarm goes off, it calls a BIOS function that fires INT 4Ah. You can write values directly to the CMOS ram by writing the address you want to write to on port address 0x70. You can then read or write a value in that ram address by using port address 0x71. I have a couple of programs that access the CMOS through these ports. Let me know if you want some C source.



    : I'v tryed the Assembler messageboard, but nobody answerd. So, now I'm asking you.

    :

    : How do I use them?

    : Do they activate any interrupt?

    : What interrupt?

    :






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