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Cmos

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Submitted By lovefor25
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Randy Ramirez
NT1110
2/12/2014

C-mos Complementary metal–oxide–semiconductor (CMOS) Pronouncedsee-moss, CMOS is a widely used type of semiconductor. CMOS semiconductors use both NMOS (negative polarity) and PMOS (positive polarity) circuits. Since only one of the circuit types is on at any given time, CMOS chips require less power than chips using just one type of transistor. This makes them particularly attractive for use in battery-powered devices, such as portable computers.Personal computers also contain a small amount of battery-powered CMOS memory to hold the date, time, andsystem setup parameters.
CMOS is an on-board semiconductor chip powered by a CMOS battery inside computers that stores information such as the system time and date and the system hardware settings for your computer. In the picture to the right, is an example of the most common CMOS coin cell battery used in a computer to power the CMOS memory.
A Motorola 146818 chip was the first RTC and CMOS RAM chip to be used in early IBM computers. The chip was capable of storing a total of 64 bytes of data. Since the system clock used 14 bytes of RAM, this left an additional 50 bytes of space that was available for IBM to store system settings. Today, most computers have moved the settings from a separate chip and incorporated them into the southbridge or Super I/O chips.
The standard lifetime of a CMOS battery is around 10 Years. However, this can vary depending on the use and environment that the computer resides. When the battery fails the system settings and the date and time will not be saved when the computer is turned off until the battery has been replaced.
The BIOS and CMOS are often times thought to be the same thing, but they are not. They are two different components of a computer, but they do work together to make the computer function properly.
The BIOS is a computer chip on

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