Passwords Stored On CMOS, ROM BIOS, Saving CMOS Setup Information

Passwords Stored On CMOS

Access to a computer can be controlled using startup passwords, sometimes called power-on passwords.

During booting or startup, the computer asks for a password. If the correct password is not entered, the booting process is terminated. This startup password is stored on the CMOS chip and can be changed by accessing the setup screen. However, you must know the password to access the setup screen. Many computers also provide a jumper near the CMOS chip that, when set to ON, causes the computer to revert to factory or default CMOS settings. Placing a jumper on these pins can disable a password because the computer no longer remembers the changes that were made to the settings.

Saving CMOS Setup Information

There are several utility software programs, including Norton Utilities, that you can use to back up setup information to a disk that can be used to recover lost setup information. Setup information on a PC can be lost if the battery dies or is replaced. Possible errors and events that might indicate that setup information is lost are: An early indication of a weak battery is that the PC loses the correct date and time when turned off.

A message at startup says, “Hardware information is lost.” A dead or poorly connected battery can cause this type of error. For both of these situations, the remedy is to replace the battery and restore the CMOS settings.

ROM BIOS

ROM BIOS is a group of programs permanently stored on a ROM chip or chips on the systemboard that manages the most fundamental communications between software and hardware. The two functions of ROM BIOS are to: Gather configuration information and initialize the computer when it is first turned on Provide software to communicate with various hardware components when the operating system is functioning ROM BIOS chips can also be present on other hardware devices, such as the video card shown below. In general, ROM BIOS chips hold programs or software that tell the CPU how to perform many fundamental input/output tasks that manage the computer. During fabrication, a ROM chip has software instructions permanently etched into it which can never be erased. However, there are now ROM chips on the market that actually can be reprogrammed. Called Flash ROM, the software stored on these chips can be overwritten by new software that will remain on the chip until it is overwritten also.