how does the computer clock work even when the machine is off for days ?

Answer 1

Also known as a RTC/NVRAM or CMOS RAM, CMOS is short for " Complementary Metal-Oxide Semiconductor " . CMOS is an on-board semiconductor chip powered by a CMOS battery inside IBM compatible computers that stores information such as the system time and system settings for your computer. As long as the CMOS battery holds charge the computers date and other such data will be fine. When the CMOS Battery gets drained or stops working that is when the computer loses time, forgets about the Drives and all that. Normally The CMOS battery can easily last more than 5 years under regular usage of the computer. It gets trickle charged all the time that you use the computer.

Answer 2

There's actually an internal battery that keeps a lil clock running in there. It's the same device that keeps the Bios of the system. It has to save all of the information even when the computer's not powered and even if you swap out hard drives.

Answer 3

There is a small rechargeable Clock Battery which is built into the computer to maintain the time.

You can also synchronize (Windows XP) your computer watch with Atomic watches using the http://nist.time.gov/ or other similar web-sites.

This helps the computer to maintain the data and time stamps on the files

Answer 4

There is something called a "CMOS" which is installed on the motherboard. CMOS is responsible for keeping the correct time and date. Since it works on its own battery, it does not need the computer to be on for it to work. If you look inside your computer, on the motherboard, you should see a battery roughly the size of a nickel. This is the CMOS battery. BTW, CMOS stands for "Complementary Metal Oxide Semiconductor."

Answer 5

Has an internal battery that runs the CMOS. Take the computer apart and you'll see a watch-like battery attached to the motherboard.

Answer 6

battery ;)

there's a small battery in every computer, so even when the computer is shut down, the clock works through the battery

Answer 7

A computer comes with a built-in battery for keeping time while it's turned off.

Answer 8

There is a little battery inside.
some times it stops working and the clock does the same.
i forgot the name of the battery i'll add the name if i remember it.

Answer 9

There's a battery on the Mother board

Answer 10

Just like a battery operated watch