2We have covered the following subjects: BIOS ROMCMOS & CMOS BatteryConfiguring the BIOSConfiguring the BIOS. ContConfigurable DevicesUn configurable DevicesOption ROMDevice Drivers, Accessing CMOS Setup, Editing The BIOS Parameters, Navigating, Saving and ExitingSummary
3BIOSThe BIOS program controls the start-up process and loads the operating system into memory.The BIOS is an example of firmware.Most BIOS chips are 64k in size, though there is 384k address space available for the BIOS to use.SCSI devices include a BIOS chip on a device itself. These devices have their own ROM chip called an option ROM.What is the BIOS?BIOS stands for, Basic input output system. The BIOS is a program stored in a read-only memory (ROM) chip that the CPU automatically loads and executes when it receives power.
4CMOSThe CMOS battery can be a low-voltage dry cell, lithium mounted on the motherboard, or even AA batteries in a housing clipped on a wall inside of the case. The electric current is about 1 millionth of an amp and can provide effective power for years.If the voltage of the battery drops significantly, you may lose your CMOS settings every time you power-off or power-on your computer. If a CMOS battery fails, replace it and afterwards re-enter the CMOS information.What is CMOS?CMOS stands for Complementary Metal-Oxide Semiconductor (CMOS).CMOS memory is a special RAM chip powered and maintained by a small battery that holds basic configuration data your computer needs in order to start.
5Configuring BIOS System Time/Date - Set the system time and date Boot Sequence - The order that BIOS will try to load the operating systemPlug and Play - A standard for auto-detecting connected devices; should be set to "Yes" if your computer and operating system both support itMouse/Keyboard - "Enable Num Lock," "Enable the Keyboard," "Auto-Detect Mouse"...Drive Configuration - Configure hard drives, CD-ROM and floppy drivesMemory - Direct the BIOS to shadow to a specific memory addressSecurity - Set a password for accessing the computerPower Management - Select whether to use power management, as well as set the amount of time for standby and suspendExit - Save your changes, discard your changes or restore default settingsTo enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use "Esc," "Del," "F1," "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is usually a line of text at the bottom of the display that tells you "Press ___ to Enter Setup."Once you have entered setup, you will see a set of text screens with a number of options. Some of these are standard, while others vary according to the BIOS manufacturer. Common options include:
6Configuring BIOS. ContBe very careful when making changes to setup. Incorrect settings may keep your computer from booting.When you are finished with your changes, you should choose "Save Changes" and exit. The BIOS will then restart your computer so that the new settings take effect.The BIOS uses CMOS technology to save any changes made to the computer's settings.With this technology, a small lithium or Ni-Cad battery can supply enough power to keep the data for years. In fact, some of the newer chips have a 10-year, tiny lithium battery built right into the CMOS chip!
7Configurable Devices The main bootable devices in the BIOS are: Hard Disk DrivesFloppy DrivesCDROM DrivesThen you have the Boot device priority:1st Boot Device [Floppy drive]2NDBoot Device [CDROM]3rdBoot Device [Hard Drive]4thBoot Device [ ]
8Un-configurable Devices A computer system can contain several BIOS firmware chips.The motherboard BIOS typically contains code to access fundamental hardware components such as the keyboard, floppy drives, ATA (IDE) hard disk controllers, USB human interface devices, and storage devices.In addition, plug-in adapter cards such as SCSI, RAID, Network interface cards, and video boards often include their own BIOS, complementing or replacing the system BIOS code for the given component.Plug and play and hot swappable devices are not configurable in the BIOS because the Plug and play and hot swappable devices also have BIOS.
9Option ROMAn Option ROM typically consists of firmware that is called by the system BIOS. For example, an adapter card that controls a boot device might contain firmware that is used to connect the device to the system once the Option ROM is loaded.
10In this short video, which can be paused and rewound, you can see how to: Access CMOS SetupNavigate around CMOSEdit the BIOS ParametersFind Device DriversSave and Exit
11Summary So what have we talked about? We have talked about the CMOS & BIOS. We hope that this presentation has helped you to understand the BIOS & CMOS better.Any Questions?