Computer Basics

1
Computer Basics

• An overview of computer hardware

ICT Tools Computer Basics
2
Types of Computers

• Computers come in
• all shapes and sizes,
• from tiny PDAs
• (personal digital
• assistants) to PC
• (personal computer)
• towers.

Handheld (HPC)
PDA
Laptop
Desktop
Tower
Workstation
ICT Tools Computer Basics
3
Computer Structure

• The diagram below shows a simple structure for
  the
• operation of a computer. Data is obtained for
• processing by the computer and then the results
  of the
• processing are output from the system.

ICT Tools Computer Basics
4
Input

• There are a wide range of input devices. Some of
  these
• input devices make use of human touch, light,
• magnetism, sound and control sensors.

ICT Tools Computer Basics
5
The Processor

• The Central Processing Unit (CPU) can be
  considered the brains
• of your computer. It consists of a single chip
  inside a computer that
• does most of the work. It takes the information
  from the input
• devices and instructions from memory, processes
  the information
• and then sends the result to storage or to an
  output device.
• Processors inside a modern PC include Intel
  Pentium III and Intel
• Celeron.
• The power of the processor is indicated by its
  operating speed
• measured in MegaHertz, (MHz).

ICT Tools Computer Basics
6
Types of Memory

• All computers have memory to store instructions
  and
• data. There are two main types of memory
• RAM (random access memory)
• This is a temporary storage for data. Typical
  RAM in a desktop PC may be 64 megabytes (MB). The
  RAM clears when your computer is switched off.
• ROM (read only memory)
• This is memory stored in a chip which is not
  lost when the power is turned off. On most PCs
  this memory is quite small. It contains the
  essential instructions for the computer to start.
  

ICT Tools Computer Basics
7
Data Storage

• Computers need both long-term storage (e.g.
  saving a
• graph to be printed out at a later date) and
  short term
• storage (eg remembering subtotals in
  calculations).
• Short term storage
• Computers use the RAM to store data temporarily
  while
• you work on it. Once you are happy with the job,
  you
• store it on the hard disk.
• Long term storage
• Floppy disks, magnetic tape, etc can be used to
  offload
• confidential data from the hard disk.

ICT Tools Computer Basics
8
Modem

• This is a device that allows computers to
  transmit information to one another via an
  ordinary telephone line. A modem can be either
  internal or it can be an external device.

ICT Tools Computer Basics
9
Parts of a PC

• A PC is a small desktop computer,
• normally made up of three basic groups
• a base unit containing processor, memory and
  disc drives
• a keyboard with a mouse and a monitor
• peripherals additional devices connected to the
  computer.

ICT Tools Computer Basics
10
Parts of a PC
ICT Tools Computer Basics
11
Inside a PC

• If you were to remove the outer casing of your PC
  you could look around inside, and you would find

ICT Tools Computer Basics
12
Inside a PC
The power supply converts the electricity from
the wall outlet into the correct voltage for the
computer.
A peripheral includes such things as a monitor,
mouse, keyboard, modem, scanner, digital camera,
and printer. Many of these devices attach to a
expansion card.
Microprocessor a small, integrated electronic
circuit that can performs specific tasks.
Microprocessors (or chips) are located in all
parts of the hardware.
Hard drive This is entirely internal. It is a
rectangle about the size of a medium paperback
book.
ICT Tools Computer Basics
13
Behind a PC
External devices connect to the computer in the
back. the arrangement of these is quite varied
from machine to machine. Note that many of the
connectors come in two types male and female.
The male has the pins while the female has the
holes. In Activity 2, you will look at these
connections in more detail.
Serial Male
Serial Female
ICT Tools Computer Basics
14
In this section

• you will become more familiar with the terms used
  by computer manufacturers when discussing
  computer specifications
• you can use this knowledge to will help you to
  choose the right system for your needs.

ICT Tools Computer Basics