Presentation on theme: "To Navigation page. We have covered the following subjects: BIOS ROM CMOS & CMOS Battery Configuring the BIOS Configuring the BIOS. Cont Configurable."— Presentation transcript:
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We have covered the following subjects: BIOS ROM CMOS & CMOS Battery Configuring the BIOS Configuring the BIOS. Cont Configurable Devices Un configurable Devices Option ROM Device Drivers, Accessing CMOS Setup, Editing The BIOS Parameters, Navigating, Saving and ExitingDevice Drivers, Accessing CMOS Setup, Editing The BIOS Parameters, Navigating, Saving and Exiting Summary
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. The 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 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. The 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.
To 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: System Time/Date - Set the system time and date Boot Sequence - The order that BIOS will try to load the operating system Plug and Play - A standard for auto- detecting connected devices; should be set to "Yes" if your computer and operating system both support it Mouse/Keyboard - "Enable Num Lock," "Enable the Keyboard," "Auto- Detect Mouse"... Drive Configuration - Configure hard drives, CD-ROM and floppy drives Memory - Direct the BIOS to shadow to a specific memory address Security - Set a password for accessing the computer Power Management - Select whether to use power management, as well as set the amount of time for standby and suspend Exit - Save your changes, discard your changes or restore default settings
Be 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!
The main bootable devices in the BIOS are: Hard Disk Drives Floppy Drives CDROM Drives Then you have the Boot device priority: 1 st Boot Device [Floppy drive] 2 ND Boot Device [CDROM] 3 rd Boot Device [Hard Drive] 4 th Boot Device [ ]
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. 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.
An 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.
Access CMOS Setup Navigate around CMOS Edit the BIOS Parameters Find Device Drivers Save and Exit In this short video, which can be paused and rewound, you can see how to:
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?