Hardware - Clydebank High School

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7 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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Hardware

The physical components of a computer system.
Everything you can see and touch.


Block Diagram

PROCESSOR

Backing Storage

Main Memory

Output Devices

Input Devices

Processor


A processor is a chip that responds to and processes the
basic instructions that drive a computer.


The processor in a personal computer is often called a
microprocessor.
Pentium 4 Processor



The processor is like the ‘brain’ of the computer system.
(BUT not a real brain as a computer cant think or act for
itself)

Instructions

Execution

Action

A set of
instructions
that control
how a
computer
works is
called a
program.

The
process of
carrying
out the
instruction
s in a
computer
program.

The
instruction
is carried
out.

Computers can carry out instructions very quickly
because the processor can process billions of
instructions every second.

Main Memory


The processor can’t store a whole program at the one
time. A computer must have memory to store programs
and data its not using at any particular time.


There are
two
types of memory chips used for a different
purpose in a computer system.


RAM and ROM

Random Access Memory (RAM)


Is the place in a computer where the operating system,
application programs, and data in current use are kept so
that they can be quickly reached by the computer's
processor.


RAM is much faster to read from and write to than the other
kinds of storage in a computer.


The data in RAM stays there only as long as your computer
is running. When you turn the computer off, RAM loses its
data.

Read Only Memory (ROM)


ROM can be used to store programs and data permanently.


Data cannot be easily written to ROM, depending on the
technology used in the ROM, writing may require special
hardware, or may be impossible.


A computer's BIOS may be stored in ROM

RAM V’s ROM

RAM

RAM holds programs and
data temporary.


Program and data are lost
when the computer is
switched off.


RAM holds programs that
are currently running on
your computer.

ROM

ROM holds programs and
data permanently.


The contents of ROM are
not lost when the computer
is switched off.


ROM hold programs
that
has been programmed
onto the chip at the factory
and cannot be changed

http://video.howstuffworks.com/hsw/player.htm?v=Computer_Tour


Change in Technology



The price of memory chips is continuing to go down.


The memory size of computers (ROM and RAM) has gone
up.


Chips work faster and can handle more data in a single
operation.


Complete computers can be produced on a single chip.


Computers are now tiny, for example palmtop computers.

Types of Computers




Palmtop Computer



Laptop Computer



Tablet Computer



Desktop Computer



Server Computer



Mainframe Computer



Supercomputer



Palmtop Computer
-

Personal Digital Assistants (PDA)


Palmtops are tightly integrated computers that often use
flash memory instead of a hard drive for storage.


These computers usually do not have keyboards but rely
on touchscreen technology for user input with a stylus.


Palmtops are typically smaller than a paperback novel,
very lightweight with a reasonable battery life.


Most types use a LCD screen as the input device.

Laptop Computer


This is a compact type of computer that can run on
batteries that is entirely
portable
. Normally has a hard
disk, floppy disk and a CD
-
ROM drive.


Uses an LCD/TFT screen as an output device. LCD use
less power
.


Laptop computers typically use a track pad or a raised
button to control the pointer on the screen.


Tablet Computer


A type of notebook computer that has an LCD screen on
which the user can write using a special
-
purpose pen, or
stylus
.


The handwriting is digitized and can be converted to
standard text through handwriting recognition, or it can
remain as handwritten text.


A keyboard can be attached for data entry.

Desktop Computer

Most desktops come with the following:


Monitor (LCD, TFT at an extra cost)


Full size keyboard (function keys, numeric keypad)


Mouse with a scroll wheel (wireless at an extra cost)


Hard Disk


Floppy Disk Drive (several manufactures do not include
these)


CD
-
ROM Drive (may have a CD rewriter)


DVD
-
ROM Drive (may have a DVD rewriter)


Modem

Desktop Computer


cont..


Loudspeakers


Microphone

Peripheral devices may come with your computer such as:


Printer


Scanner


Web Camera

Server Computer

A computer that delivers information and software to other
computers (clients) linked by a network.


A network interface card is required in order to connect to
a network.


Different types of servers:



File Server (storage of users programs and data)



Printer Server (queuing facility)



CD
-
ROM server (access data from one or more CD
-
ROMS held within it)

Mainframe Computer

Very large computer system which can process very large
amount of data at a high speed.


It may be connected to hundreds of user
terminals.


Vast amount of RAM and many extra peripherals such as
tape and disk drives.


The ‘dumb’ terminal has no processor and no local storage
devices. All that is required is a screen and a keyboard.

Multi
-
access system

More than one person using a
mainframe computer system at
the same time

Multi
-
tasking system

More than one program running
on a computer system at the
same time

Super Computer

Used for intensive mathematical calculations such as:


Weather and climate forecasting


Car Design


Aerospace Engineering


Digital Animation in motion pictures.