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UNIT 3 COMPUTER
SYSTEMS
ASSESSMENT 1 – THE STRUCTURE OF A COMPUTER SYSTEM
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P1- IDENTIFY THE
COMMON COMPONENTS
OF A COMPUTER SYSTEM
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TASK 1
You are required to produce a leaflet describing
the main components [both hardware and
software] of a computer including peripherals.
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COMPONENTS OF A COMPUTER
SYSTEM
You need to describe the components and
features also explain what job each component
does and how they are connected
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HARDWARE COMPONENTS
• Hardware comes in a variety of different
component types. Although they can be some
differences between manufactures
• You should learn what job each component does
and how they are connected.
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• Hardware is any physical component in a
computer system; something that is tangible and
can therefore be ‘seen’ and ‘touched’
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Processor speed & Type
Ram, Rom, cache
[memory]
Motherboard
Storage
CD Rom
CDR CDRW & DVDR
DVDRW, BD BLURAY
Hard drive
Flash Drives
USB storage devices
Memory Stick
Costs
Input
Graphics tablet
Mouse
Digital camera
Scanner
Touch Screen
Gaming controller
Microphone
Keyboard
Output medium
Printer
Computer monitor
Sound- speakers
Computer Network
connectivity eg 3G, Wireless,
Bluetooth, NIC
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Hardware
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Motherboard
• All computer systems , no matter what size., have a
‘main’ board of some kind
• The most popular is called ATX [advanced technology
extended] compatible.
• The following components are connected directly to the
motherboard – CPU, RAM & the CHIPSET
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• Largest component – all the other components are
plugged into or connected to the motherboard.
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CPU-Processor
• It is the heart of the computer system,
allowing the operating system and other
programs to run.
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• The central processing unit is another name
for the processor. It is a chip that fits into a
socket on the motherboard.
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CPU-Processor
• CPUs are usually the most expensive component of
a system, manufactured by either Intel or AMD
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• Every program consists of instructions for the
processor that are decoded and actioned inside the
processor to make them work
• AMD – Athlon and Opteron
• Intel – Pentium and Celeron
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Speed
• The frequency of the processors internal clock is
measured in [Hz].
• Some CPU’s have multiple ‘cores’ which can work
independently or can combine to process data
faster.
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• CPU’s are usually 32-bit or 64-bit. This describes
the size of data and instructions it can process.
• CPU performance is measured by a combination or
its bit size, number of cores and frequency: bigger is
usually better!
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Cache memory
• The FAT (File Allocation Table) is held on the
disk to connect names of files and folders to
where they actually are on the disk. When a
file is opened or saved the disk address
needs to be looked up in the FAT before the
file can be found.
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• Is very fast electronic memory between RAM
and another device, used to make the
system run faster.
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RAM
• When the power is removed the data is lost
– this is what we call volatile storage. RAM
is a key factor in a good computer system
performance [more is better]
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• RAM stands for random access memory. Is
to store data and instructions temporarily
when a program is being run by a CPU.
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• There are many types, sizes and speeds of
RAM, with DIMMs [Dual Inline Memory
Module] and DDR [Double Data Rate]
being the most common.
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RAM
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Hard
Software being run and
documents being opened
disk
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Cache
RAM
Cache
Documents being saved
Processor
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• If data is required from the drive, the
required data is brought to cache, as well
as the next data on the disk, so if the
computer needs this as well, it is already in
the cache
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Cache
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Chipset
• Motherboards make use of many specialist microchips [‘chips’
for short] The common ones are:
• Southbridge – which manages traffic between slower
motherboard components.
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• Northbridge – which manages data traffic between faster
motherboard components [RAM, CPU and video card].
In addition the motherboard may have chips dedicated to:
• Video
• Sound
• Network connectivity
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• Alternatively these can be separate cards which
are plugged into the motherboard through
extension slots.
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• Video
• Sound
• Network connectivity
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STORAGE DEVICES
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Hard disks [drives] Internal
• These are magnetic data storage units and they store vast amounts
of data and spin at speeds of around 7200 rpm [revolutions per
minute]. Although hard disks are typically stored inside the base
unit [or laptop] they can also be purchased as an external device,
usually connected by USB [Universal serial bus] or e SATA cables.
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• Internal hard disks are connected to the motherboard by either a
PATA [Parallel Advance Technology Attachment] or the newer SATA
[Serial ATA] connection.
• Most new computer systems are using SATA drives and often have at
least 500 GB storage
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OPTICAL DRIVES
• Drives are usually marked to indicate what type of discs they
will accept The typical data capacity of these discs is as given
below:
CD:650-700MB
DVD: 4.7 – 16GB
BD:25 – 128GB
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• Use a laser to read\data from CD, DVD or a BD [Blu – ray disc]
Most drives can use either read-only discs, such as CD-ROMs
and DVD-ROMs, or can be used to record data on recordable
or rewriteable discs.
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Flash Drives
• Relatively inexpensive and easy to use, flash drives connect to,
modern computer systems via a USB port storing anything
between 16MB and 250GB.
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• Use a special type of electronic memory which can be written
very quickly and remains intact even when the device is
removed from the computer system’s power. This makes
them ideal for medium and long term data storage.
• The USB hub it connects to is built into the motherboard
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• The following components are connected
to the motherboard via external ports
[usually on the ‘backplane’ of the
motherboard which is visible on the back
of the base unit].
• These components are peripheral
[connected outside the base unit] and are
classified as input devices.
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Peripherals
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INPUT DEVICES
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Touch Screen
• Touch screens are easy they only require the users hand.
Combined with simple user friendly icon based interface,
even non technical users can interact with a computer
system.
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• Is new popular in mobile phones, GPS devices, public
access points, bank ATMs and hand held games consoles.
• The surface project from Microsoft is a good showcase
for this technology
www.microsoft.com/surface/en/us/default.aspx]
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• Alternative way to draw instead of using a
mouse, greater precision for drawing.
Professional digital artists will use a tool like this
when using graphical applications software such
as Adobe Photoshop.
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Graphics Tablet
• Graphic tablets come complete with a stylus and
often comes in A5, A4 and A# sizes. They are
usually connected to a computer system via USB
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• Can be use with a PC or Apple Mac most are
specific to a chosen games console. Most
contain force-feedback technology which
‘rumbles’ the controller in the user’s hand to
reflect on-screen events.
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Game Controllers
• Some controllers use a proprietary connection
[specific to a particular console] most modern
devices use either USB or wireless connections.
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• Is used to convert sound waves made by
human speech into electrical signals which
can be used to control a computer system
or talk to other users via internet
telephone services such as Skype
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A Microphone
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Keyboard
A Mouse
• Uses either mechanical roller ball or optical lightemitting dipoles and sensors to move the pointer
on the screen.
• A mouse is a key component of a modern GUI
either wireless or USB or PS/2 connections
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• Qwerty keyboard basic input device Most PC
keyboards are wireless or USB or PS/2
connections.
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OUTPUT DEVICES
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• Produces monochrome, grey scale or colour
prints containing text and / or images. Inkjet and
laser. Inkjet uses wet cartridge ink laser works
similar to photocopiers by using dry toner which
is heat-bonded to certain points of the page.
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Printer – other peripherals
• Most printers are wireless, USB or much older
parallel port connections.
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Monitors
• LCD have become standard. Connections to
computer systems are usually by the older 15pin for VGA connecter for newer typically 29-pin
DVI digital interface.
• The type of connection used must be compatible
with the computer system’s video card.
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• Older – CRT diminishing in use due to bulky
nature and higher power consumption.
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• Connects to the sound card. Converts electrical
signals into sound waves. Two speakers are
common offering stereo sounds. More complex
speaker systems are possible depending on the
sound card.
• You can set up 5.1 systems five speakers plus a
sub woofer for lower frequency ‘bass’ sounds.
• Speakers can be connected\wireless or USB
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Speakers
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Network connectivity
• 3G or 4th generation mobile telephone technology, can
be used to transmit data over a cellar network between
two different computer systems.
• Although the technology is built into #G phones,
tradition PC systems such as desktops or notebook can
make use of USB 3G Dongles to access the same
network.
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• In addition to input and output devices computers can be
connected together. Any device that helps to achieve
this comes under the classification of network
connectivity.
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Wi-Fi networks
• It is possible to connect a USB wireless dongle that will
do the same job. Although not fast, flexible or powerful
as a Wi-Fi network., Bluetooth connectivity can be a
useful tool when transmitting data between a mobile
telephone and a computer system.
• .
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• Can be accessed by an appropriate wireless network
controller and many devices have these built-in [for
example, Apple I phone, Nintendo Wii Sony Play Station
and most notebooks.
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Wi-Fi networks
• A network interface card [NIC} usually plugs into a
motherboard of a computer system. Many different
types [and speeds] exist and it is not uncommon to find
its circuitry built into the motherboards of most desktops
PC’s, laptops and netbooks.
• Although some NIC’s use a wired [Ethernet] connection,
others use wireless connectivity sand often have a visible
antenna
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• Inexpensive USB Bluetooth dongles enable a user to back
up mobile telephone data [such as pictures, SMS text] to
their computer system or uploaded music to them
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