Chapter 4: System Bios; What Is The Bios; The Power-On Sequence - Viglen Vig644M Manual

Chapter 4: System BIOS

What is the BIOS?

The BIOS (Basic Input Output System) is an important piece of software which is stored
in a ROM (Read Only Memory) chip inside the computer. It consists of the basic
instructions for controlling the disk drives, hard disk, keyboard and serial/parallel ports.
The BIOS also keeps a list of the specifications of the computer in battery-backed RAM
(also known as the CMOS RAM) and provides a special Setup program to change this
information.
The BIOS in your Viglen computer is guaranteed to be fully compatible with the IBM
BIOS. It has been written by Phoenix Award BIOS, an industrial leader in the field of
BIOS software.

The Power-On sequence

When the computer is first switched on, certain instructions in the BIOS are executed to
test various parts of the machine. This is known as the POST (Power-On Self Test)
routine. When you switch the computer on (or when you press the Reset button or press
<Ctrl> + <Alt>+ <Delete> keys, which has the same effect), you can see on the monitor
that it counts through the memory, testing it. The floppy disk drives are then accessed
and tested, and the various interfaces are checked. If there are any errors, a message is
displayed on the screen.
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V1.0 Vig644M Motherboard Manual