The Setup program

The Setup program

You communicate with the BIOS programs and the CMOS memory through the so-called Setup program.
Typically you reach the Setup program by pressing [Delete] immediately after you power up the PC. That brings you to a choice of setup menus. You leave Setup by pressing [Esc], and choose "Y" to restart the PC with the new settings. Generally, you should not change these settings, unless you know precisely what you are doing.
The Setup program can do many things for you. You have to enter Setup, if you install a different type or additional disk drive in your PC. Certain BIOS's will also need adjustment of its settings, if a CD ROM drive is installed on one of the EIDE channels.

Modifying the boot sequence

You can change the boot sequence from A:, C: to C:, A:. That means, that the PC will not try to boot from any diskette in the A drive. That will protect you from certain virus attacks from the boot sector. Also, the boot process will not be blocked by any diskette in the A drive.

If you need to boot from A-drive (for example, if you want to install Windows 97 ), you have to enter Set-up again, and change the boot sequence to A:, C:. That is no problem.

Power Management

You also use the Setup program to regulate Power Management, which is the power saving features in the system board. For example, you can make the CPU shut down after one minute of no activity. There are plenty of settings available in this area.

Password Protection

You protect the Setup program with a password. This is used widely in schools, where they do not want the little nerds to make changes in the setup. Please remember the password (write it down in the mainboard manual). If you forget it you have to remove the battery from the mainboard. Then all user-input to the CMOS is erased - including the password.

Here is a scanned image from a Setup program. It belongs to my favorite board (from ASUS). Here you see the "BIOS Feature Setup," where you can select start-up choices:

Here we are are in the special "Chip set Feature Setup." These choices relate to the chip sets and, most likely, need no changes:

The BIOS programs

During start-up. the BIOS programs are read from a ROM chip. BIOS is abbreviation of Basic Input Output System and thoseare programs, which are linked to specific hardware systems. For example, there is a BIOS routine, which identifies how the PC reads input from the keyboard.

BIOS is a typical link in the IBM compatible PC design. The BIOS programs control hardware, the user (programmer) controls hardware via a call to BIOS

BIOS typically occupy 1 MB, and the programs are saved ROM chips on the system board.
During start-up, BIOS is read from ROM chips. That information is supplemented with the system data saved in CMOS.

Furthermore, there is BIOS code on the expansion cards. The expansion cards are external hardware, as interpreted by the system board, and the BIOS code, which is linked to the expansion card, must be included in the configuration. Therefore, this expansion card ROM is read during start-up, and the program code is woven together with other BIOS data. It is all
written into RAM, where it is ready for the operating system, as you can see here:

Otherwise, the BIOS routines are not always in use. They can be regarded as basic program layers in the PC. Many programs routinely bypass BIOS. In that case, they "write direct to hardware", as we say. Windows contains program files, which can be written directly to all kinds of hardware - bypassing BIOS routines. One example is the COM ports. If you use
the BIOS routines connected with them, you can transmit only at max. 9600 baud on the modem. That is insufficient.

Therefore, Windows will assume control over the COM port.


BIOS programs can be updated. The modern system board has the BIOS instructions in flash-ROM, which can be updated. You can get new BIOS-software from your supplier or on the Internet, which can be read onto the system board. The loading is a special process, where you might need to change a jumper switch on the system board. Usually, you do not need to do this, but it is a nice available option.


The latest PC electronic standard is called ATX. It consists of a new type system board with a specific physical design smaller than the traditional board (30.5 cm X 19 cm). The I/O connectors COM1, COM2 and LPT, keyboard, mouse and USB are mounted directly on the system board. The ATX board requires specifically designed chassis's with an I/O access opening measuring 1¾ by 6¼ inch. ATX is designed by Intel, but has gained general acceptance.

The ATX system board is more ”intelligent” than the ordinary type. In a few years, it will be wide spread. It includes advanced
control facilities, where the BIOS program continually checks the CPU temperature and voltages, the cooling fans RPM, etc. If
over heating occurs, the PC will shut down automatically. The PC can also be turned on by for example modem signals, since