Glossary 117
Glossary
AC adapter
The AC (or alternating current) adapter regulates current coming into your
computer from the wall outlet. The current at the wall outlet is alternating current
and needs to be changed by the adapter to DC (direct current) before your
computer can use it for power.
ACPI
ACPI (Advanced Configuration and Power Interface)- a method for describing
hardware interfaces in terms abstract enough to allow flexible and innovative
hardware implementations and concrete enough to allow shrink-wrap OS code to
use such hardware interfaces.
BIOS
BIOS stands for basic input/output system. The BIOS is software (often called
firmware) that is independent of any operating system. It enables the computer to
communicate with the screen, keyboard, and other peripheral devices without
using programs on the hard disk.
The BIOS on your computer is flash BIOS, which means that it has been recorded
on a flash memory chip that can be updated if needed.
Boot
To start your computer. A cold boot resets the entire computer and runs through
all computer self-tests. A warm boot clears out computer memory only.
Boot disk
A disk containing operating system programs required to start your computer. A
boot disk can be a floppy disk, hard drive, or compact disc.
Byte
The basic unit of measure for computer memory. A character—such as a letter of
the alphabet—uses one byte of memory. Computer memory is often measured in
kilobytes (1,024 bytes) or megabytes (1,048,576 bytes).
Each byte is made up of eight bits. For more information on bytes and bits, see an
introductory book on computers.
Cache memory
Cache is very fast, zero-wait-state memory located between the microprocessor
and main memory. Cache reduces the average time required by the
microprocessor to get the data it needs from the main memory by storing recently
accessed data in the cache.
