Transcript Computer basics

Computer Basics
An overview of computer hardware
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Types of Computers
Handheld (HPC)
Desktop
PDA
Laptop
Computers come in
all shapes and sizes,
from tiny PDAs
(personal digital
assistants) to PC
(personal computer)
towers.
Tower
Workstation
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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.
Input
Process
Output
Data
Storage
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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.
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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).
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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.
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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.
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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.
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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.
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Parts of a PC
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Inside a PC
If you were to remove the outer casing of your PC
you could look around inside, and you would find:
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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.
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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
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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.
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