pctechguide.com

  • Home
  • Guides
  • Tutorials
  • Articles
  • Reviews
  • Glossary
  • Contact

CMOS – complementary metal oxide silicon – RAM chips on motherboards

Motherboards also include a separate block of memory made from very low power consumption CMOS (complementary metal oxide silicon) RAM chips, which is kept alive by a battery even when the PC’s power is off. This is used to store basic information about the PC’s configuration: number and type of hard and floppy drives, how much memory, what kind and so on. All this used to be entered manually, but modern auto-configuring BIOSes do much of this work, in which case the more important settings are advanced settings such as DRAM timings. The other important data kept in CMOS memory is the time and date, which is updated by a Real Time Clock (RTC).

Battery

The CMOS memory is usually located with the real-time clock in the motherboard chipset or in a separate real-time clock chip. The PC reads the time from the RTC when it boots up, after which the CPU keeps time – which is why system clocks are sometimes out of sync. Rebooting the PC causes the RTC to be reread, increasing their accuracy.

In modern-day PCs the nonvolatile BIOS memory is generally an EEPROM or Flash memory chip. There is still a backup battery involved, but its role is not to maintain the data stored in the RAM, only to keep the RTC chip operational.

  • Evolution of the motherboard
  • BIOS – What motherboard BIOS does for a PC
  • CMOS – complementary metal oxide silicon – RAM chips on motherboards
  • EFI – Extensible Firmware Interface – explained
  • Motherboard form factors
  • Baby AT (BAT) Motherboard Form Factor
  • LPX – Low Profile eXtension motherboard form factor
  • ATX form factor
  • NLX – New Low profile eXtended – form factor for motherboards
  • Micro ATX motherboard form factor
  • FlexATX motherboard form factor
  • BTX – Balanced Technology eXtended – Motherboard Form Factor
  • Riser architectures for motherboards
  • CPU interfaces – motherboard slots and sockets for AMD and Intel processors

Filed Under: Motherboards Tagged With: CMOS, CMOS RAM, complementary metal oxide silicon, motherboard CMOS

Latest Articles

autosave Essentials Review

AutoSave Essentials Review

PROS: AutoSave Essentials is a simple to use data backup program that is very straight forward and does an excellent job backup up data. This program is very light on system resources. CONS: No full image backup of the operating system is capable with AutoSave Essentials. This is not a big deal … [Read More...]

What is Level 1 (L1) Cache Memory?

The Level 1 cache, or primary cache, is on the CPU and is used for temporary storage of instructions and data organised in blocks of 32 bytes. Primary cache is the fastest form of storage. Because it's built in to the chip with a zero wait-state (delay) interface to the processor's … [Read More...]

Illustrated Intel Centrino Duo technology guide

In January 2006, Intel introduced the revolutionary Intel Centrino Duo Mobile Technology platform (formerly codenamed Napa), the third generation of the company's Centrino mobile processor technology bundle. Facilitating a whole new generation of thin and light notebook PCs, the following three next … [Read More...]

Gaming Laptop Security Guide: Protecting Your High-End Hardware Investment in 2025

Since Jacob took over PC Tech Guide, we’ve looked at how tech intersects with personal well-being and digital safety. Gaming laptops are now … [Read More...]

20 Cool Creative Commons Photographs About the Future of AI

AI technology is starting to have a huge impact on our lives. The market value for AI is estimated to have been worth $279.22 billion in 2024 and it … [Read More...]

13 Impressive Stats on the Future of AI

AI technology is starting to become much more important in our everyday lives. Many businesses are using it as well. While he has created a lot of … [Read More...]

Graphic Designers on Reddit Share their Views of AI

There are clearly a lot of positive things about AI. However, it is not a good thing for everyone. One of the things that many people are worried … [Read More...]

Redditors Talk About the Impact of AI on Freelance Writers

AI technology has had a huge impact on our lives. A 2023 survey by Pew Research found that 56% of people use AI at least once a day or once a week. … [Read More...]

11 Most Popular Books on Perl Programming

Perl is not the most popular programming language. It has only one million users, compared to 12 million that use Python. However, it has a lot of … [Read More...]

Guides

  • Computer Communications
  • Mobile Computing
  • PC Components
  • PC Data Storage
  • PC Input-Output
  • PC Multimedia
  • Processors (CPUs)

Recent Posts

GSM Technology

The GSM network can be divided into four main parts: The Mobile Station, which is carried by the subscriber The Base … [Read More...]

Enable Two Factor Authentication for Google Account

Protecting your online accounts is becoming more important. Everyday we hear stories of accounts being hacked and broken into. Many times these … [Read More...]

Understanding the Basics of Visual Basic Script

Visual Basic Script, derived from the programming language "Visual Basic".Excerpt from the article "Playing with VBScript: TBS Gladiators": Visual … [Read More...]

[footer_backtotop]

Copyright © 2025 About | Privacy | Contact Information | Wrtie For Us | Disclaimer | Copyright License | Authors