15 October 2012

Time tracking - the tale of RTC

Hey guys ,
sometimes it fascinates me that, we overlook the minute details of our life and go on ahead , one such detail is the the topic of this post .so , let me ask you one question , what happens when you power off your computer ? ,well the answer is simple it 'turns off' , now when you start it up again after a while , it still shows the correct time , how is that even without power supply that your computer could maintain time ? these are a few questions we will explore in this post .....

The truth ,my friends , is that even when you turn off your computer there is a component(s) that keeps on running ,called the RTC or real time clock , this is what keeps track of time.the following is a part from the wikipedia page on the RTCs,

A real-time clock (RTC) is a computer clock (most often in the form of an integrated circuit) that keeps track of the current time. Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time. 
 Again my friends the question stays the same, the computer is "powered off' so , how can this RTC keep on running without power ?, the truth is , that it can't . but that would only be half of the story there is a battery on the motherboard of a computer called the CMOS battery, it's function along with others , is to keep the RTC going when your computer ,apparently, is turned off .

These cells can last anywhere between two to ten years, depending on the motherboard, temperature and the length of time that the computer is turned  off. but this is not all in yet other situations computers maintain a sync with different on-line servers for correction of system time , as and if required ..

CMOS battery

If you want to read up more on this topic you can always ask Me in the Comments or Google :)
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