Enhanced A+ Guide to Managing and Maintaining Your PC Third Edition

Chapter 1
How Computers Work

You Will Learn…
About the functions performed by different hardware components of a microcomputer
About the three kinds of software and how they relate to one another and to hardware
How the CPU uses primary and secondary storage to manage software

Hardware and Software
Hardware
Physical components of the computer
Monitor
Keyboard
Memory chips
Hard drive
Software
Set of instructions that directs the hardware to accomplish a task

Chauffer Analogy

Functions of Hardware

Binary Number System

Hardware
Central processing unit
Most important hardware device
Receives input and sends output
Stores data and instructions; performs calculations
Requirements of hardware devices
Method for CPU to communicate with the device
Software to instruct and control the device
Electricity to power the device

Hardware Used for Input and Output
Ports
Physical connectors that allow a cable from a peripheral device to be attached
Input devices
Keyboard
Mouse
Output devices
Monitor
Printer

Ports

Input Devices

Output Devices

Hardware Inside the Computer Case
System board
Permanent storage
Floppy drive
Hard drive
CD-ROM drive
Power supply
Circuit boards
CMOS (most CPUs)
TTL
Cables

Hardware Inside the Computer Case

CMOS Chips
Require less electricity
Hold data longer after electricity is turned off
Are slower
Produce less heat

The System Board
Largest and most important circuit board
Contains the CPU

The System Board

Major Components of System Boards
For processing
CPU
Chip set that supports CPU by controlling many system board activities
For temporary storage
RAM
Cache memory

Major Components of System Boards
Allow CPU to communicate with other devices
BUS
Expansion slots
Firmware and setup information
Flash BIOS memory chip
CMOS configuration chip
Electrical system
Power supply connections

Components Used Primarily for Processing
CPU or microprocessor
Executes most computer processes
Chip set
Relieves CPU of some processing
Provides careful timing of activities to increase overall speed
Coprocessor
Supports and enhances function of some older CPUs (pre-1995)

The CPU

Temporary (Primary) Storage Devices
Used by the CPU to process data and instructions
Provided by RAM (random access memory devices)
SIMMS (single inline memory modules)
DIMMS (dual inline memory modules)
Cache memory

SIMMS and DIMMS

Cache Memory
For new CPUs
Stored inside CPU housing on a memory chip that sits close to the CPU microchip
For older CPUs
Stored on the system board either in individual chips or on memory modules called COAST (cache on a stick)

Cache Memory

Permanent (Secondary) Storage Devices
Remote to the CPU
Permanently hold data, even when PC is turned off
Most popular devices:
Hard disks
Floppy disks
Zip drives
CD-ROMs

Hard Drives

Click to go Back to Classes