A Real-Time Clock (RTC) is part of a microchip on a computer motherboard. The small memory on this chip stores time values which are usually for year, month, date, hours, minutes, and seconds. When the computer is activated, the basic input/output system reads the current time from the memory on the chip with the RTC. Computers with an older BIOS have only two-digit values for the year, newer ones have a converted four-digit value for the year. This was part of the Y2K problem.

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