INT 1aH 02H: Read Time from Real-Time Clock

 Expects: AH    02H
 Returns: AH    0
          AL    hours, in BCD
          CH    hours, in BCD
          CL    minutes, in BCD
          DH    seconds, in BCD
          DL    00h = no Daylight Savings Time option
                01h = Daylight Savings Time option
          CF    NC (0) clock operating
                CY (1) clock not operating or busy being updated
    Info: Obtains the current time from the battery-backed CMOS Real-Time

          Return values are in BCD in 24-hour format; for instance,
          CX = 1234H = 12:34pm.

          The BIOS avoids reentrancy by not returning the time if the clock
          happens to be in the process of being updated.  Thus, if CF is
          set on return, you should try a few more times before giving up.

See Also: INT 1aH (BIOS Time I/O)
          DOS fn 2cH (get system time)
          ROM-BIOS Functions