Technical The BIOS and CMOS BIOS Set-up Menu

The BIOS Setup

The BIOS provides a Setup utility program for specifying the system configurations and settings. The BIOS ROM of the system stores the setup utility. When you turn on the computer the BIOS is immediately activated. Pressing a dedicated key immediately allows you to enter the Setup utility. If you are a little late pressing the dedicated key the Power On Self Test (POST) will continue with its test routines. If you still wish to enter Setup, restart the system by pressing the 'Reset' switch or simultaneously pressing the <Ctrl>, <Alt> and <Delete> keys. You can also restart by turning off and back on again.

A PC fitted with an Award, AMI or Phoenix BIOS will display a message similar to the following, on the screen:

Press <Del> to Enter Setup

In general, you press the arrow keys to highlight items, <Enter> to select, the <PgUp> and <PgDn> keys to change entries, <F1> for help and <Esc> to quit.

Other BIOS manufacturers assign a different dedicated key than <Del>. Common instances are:

<ESC>, <CTRL-ESC>, or <CTRL-ALT-ESC>, <F1>, <F2>, <Ins> and some systems for example Dell laptops have a key with the BIOS symbol on it and can be used at anytime, not just when the system boots.

When you enter the Setup utility, the Main Menu screen will appear. The Main Menu allows you to select from various setup functions and exit choices. The various setup functions tell the operating system what type of devices are connected to your system board. Some of them are defaults required by the motherboards design, others will be dependent on the features of your system. This type of information is normally stored in battery backed CMOS SRAM so that it retains the Setup information when the power is turned off.

Most BIOS Setup menu's allow you to change the background and text colour using the <F2> key, to cycle through the available colours.

The Main Menu

A typical Award BIOS has the following sub-menu's:

• Standard CMOS Setup - This page includes all the items in a standard compatible BIOS. Configure the date and time, hard drive types, floppy drive types, primary display type and stopping the system in case of errors.
• BIOS Features Setup - This setup page includes all the enhanced features such as enabling or disabling cache memory and shadow RAM and the status of various switches such as the NUM Lock mode.
• Chipset Features Setup - This setup page includes special Chipset features such as DRAM and cache speed and enabling or disabling onboard ports such as serial and parallel.
• Power Management Setup - This setup page includes Green function features such as power management timer selectors.
• PnP/PCI Configuration - This setup page includes Plug and Play and PCI card configurations. The setup is used to route PCI interrupts to designated ISA interrupts and determine available IRQ's for PnP devices.
• Load BIOS defaults - BIOS defaults are the most appropriate values for a safe configuration.
• Load Setup defaults - Setup defaults are the most optimised values for best performance configuration.
• Integrated Peripherals - This setup page includes configuration of peripheral features and can be found in addition to the Chipset Features Setup on some motherboards, probably because that menu's screen was becoming overcrowded.
• Supervisor Password - Allows you to limit access to the Setup by configuring the system so that a password is required when you attempt to enter the CMOS Setup. The password function is disabled by default. To change the password, you must first enter the current password then type your new password at the prompt. The password is case sensitive and you can use up to eight alphanumeric characters. You need to confirm the new password by typing it in again.
  After you use this option to enable the password function, use the 'Security Option' in the BIOS Features Setup to specify whether a password is required every time the system boots or only when an attempt is made to enter the CMOS Setup.
• User Password - Allows you to limit access to the system by configuring the system so that a password is required when the system boots. The password function is disabled by default. To change the password, you must first enter the current password then type your new password at the prompt. The password is case sensitive and you can use up to eight alphanumeric characters. You need to confirm the new password by typing it in again.
  After you use this option to enable the password function, use the 'Security Option' in the BIOS Features Setup to specify whether a password is required every time the system boots or only when an attempt is made to enter the CMOS Setup.
• Password Setup - Older motherboards did not support different passwords for supervisor and user and therefore only had this one option. The password function is disabled by default. To change the password, you must first enter the current password then type your new password at the prompt. The password is case sensitive and you can use up to eight alphanumeric characters. You need to confirm the new password by typing it in again.
  After you use this option to enable the password function, use the 'Security Option' in the BIOS Features Setup to specify whether a password is required every time the system boots or only when an attempt is made to enter the CMOS Setup.
• IDE HDD Auto Detection - Automagically/automatically detect and configure your hard disk settings and enters the correct parameters in the Standard CMOS Setup. All IDE drives are detected as type 47 drives.
• Save and Exit Setup - Save any changed values to the CMOS and exit Setup.
• Exit without save - Abandon all changed values and exit the Setup.
• HDD Low Level Format - Lets you search for bad tracks and format a hard disk drive. Be warned this will destroy all data on the hard disk. Although this option is found on older motherboards and is mainly used for formatting SCSI drives it is a useful tool for detecting and marking bad sectors on a IDE drive if the drive refuses to format under DOS first. Some hard disk drive manufacturers supply their own low-level formatting program.

The section at the bottom of the screen on the Main Menu explains how to control the Setup screen.

You use the CMOS Setup program to modify the system parameters to reflect the options installed in your system and to customise your system as required. For example, you should run the Setup program after you replace the battery, install another hard drive, receive an error code at start-up, use your system after not having used it for a long time or find the original setup missing.

Note: After making and saving system changes to the Setup, you find that your computer cannot boot, some BIOS support an override to the CMOS settings that resets your system to its default. For example holding down the <End> key for a moment, while booting then resetting the system can restore the BIOS to the default setup on some systems. Unless, you are prepared for the consequences, know why you are changing a setting or like to hack your own system, I strongly recommend that you do not make any changes to the Chipset defaults because most have been carefully chosen by your motherboard and BIOS manufacturer to provide maximum performance and reliability.

Standard CMOS Set-up