## Int 1A/AH=02h

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### TIME - GET REAL-TIME CLOCK TIME (AT,XT286,PS)

    AH = 02h
    CF clear to avoid bug (see below)

    Return:
    CF clear if successful
    CH = hour (BCD)
    CL = minutes (BCD)
    DH = seconds (BCD)
    DL = daylight savings flag (00h standard time, 01h daylight time)
    CF set on error (i.e. clock not running or in middle of update)

Notes: This function is also supported by the Sperry PC, which predates the IBM AT; the data is returned in binary rather than BCD on the Sperry, and DL is always 00h. MS-DOS/PC DOS IO.SYS/IBMBIO.COM use this function to detect if a RTC is preset by checking if the returned values are non-zero. If they are, this function is called one more time, before it is assumed that no RTC is present.

BUG: Some BIOSes leave CF unchanged if successful, so CF should be cleared before calling this function

See Also: AH=00h - AH=03h - AH=04h - INT 21/AH=2Ch

Category: Bios - Int 1Ah - T

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