Working with your Computer's BIOS - CompTIA A+ 220-801: 1.1

Starting the computer

• Everything has to talk to the computer
• Keyboard language translation
• Monitor language translation
• Hard drive language translation
• CD-ROM drive language translation
• BIOS provides basic system for communicating between diverse components.  
 

 
•  BIOS- Basic Input Output System
• The firmware (software)
• The conductor of the PC orchestra
• Every PC has a BIOS 
• Nonvolatile BIOS memory-Nonvolatile BIOS memory refers to a small memory on PC motherboards that is used to store BIOS settings. It was traditionally called CMOS RAM because it used a volatile, low-power complementary metal-oxide-semiconductor (CMOS) SRAM (such as the Motorola MC146818 or similar) powered by a small battery when system power was off (called the CMOS battery).
• The term remains in wide use but it has grown into a misnomer: nonvolatile storage in contemporary computers is often in EEPROM or flash memory (like the BIOS code itself); the remaining usage for the battery is then to keep the real-time clock (RTC) going. The typical NVRAM capacity is 512 bytes, which is generally sufficient for all BIOS settings. The CMOS RAM and the real-time clock have been integrated as a part of the southbridge chipset and it may not be a standalone chip on modern motherboards.
   
• Complementary metal-oxide semiconductor (CMOS)
• Backed up with a battery
• Stores the BIOS configuration 
•  Configuration of CMOS not very large
• 128-512 bytes of content
• may be integrated into the southbridge
• The "CMOS" battery
  
• Maintains the BIOS configuration
• A bad battery will require a BIOS configuration on every boot
• Can often reset the BIOS configuration by removing the battery.

Built- in diagnostics 

Important Tips 

• Have a backup of your BIOS configuration
• Make notes
• Take a picture
• Don't make a change unless you're certain of the setting
• MAKE SURE TO BACK UP, IT CAN SAVE A LOT OF TIME!