Types and Components of Computer Systems
•Hardware & Software
• Hardware
• Tangible physical components of a computer
system
• You can feel it or touch it
• Hardware can either be internal or external
Internal Hardware Devices
•Processor
•Motherboard
•RAM & ROM
•Video & Sound Cards
•Internal Storage devices like Hard disk
drive(HDD) & Solid state drive(SSD)
External Hardware Devices
•Monitor
•Keyboard
•Mouse
•Printer
•External Storage Device
Peripheral devices:
Are all devices that can be attached
to a computer system, e.g. digital
camera, scanner.
All devices than the CPU.
Internal Computer Hardware:
1. Central Processing Unit (CPU):
The CPU interprets and executes the
commands from the computer hardware and
software. It is part of the motherboard.
A microprocessor
•is a single integrated circuit found in
PCs and many household devices.
CPU made up of:
•Control unit: controls the input and
output devices associated with the
computer
•Arithmetic and logic unit: carries out
calculations and makes logical decisions
•Immediate access store (RAM)
Motherboard:
The motherboard is a printed circuit board
found in all computers. The motherboard
allows the processor and other computer
hardware to function and communicate
with each other. It acts as a kind of ‘hub’
that other computer devices connect to. It
contains several sockets and slots to
connect the other components.
Internal Hard Disk Drive (HDD) or Solid State Drive
(SSD)
•computer’s main internal storage
•this stores the application software,
operating system and files
•they have fast data transfer rates and data
access times
•large memory capacity to store data
RAM:
• Random access memory (RAM) is an internal chip
where data is stored temporarily
• Memory can be written to and read from
• Stores anything that needs to be changed
• All program and data being used are on RAM
• Contents lost when computer is turned off
• Referred to as volatile memory
ROM:
•Read only memory (ROM) is memory used to
store permanent information
•Used to contain configuration data for a
computer etc.
•Chips cannot be altered, only read from
•Data not lost when computer is turned off
•Referred to as non-volatile memory
BIOS:
• ROM contains boot file, referred to as BIOS
(basic input/output system)
• Tells computers what to do when it first starts
• Does hardware check when computer is
turned on
• Then it loads operating system into RAM
• BIOS stores date, time and system
configuration
CMOS (Complementary Metal Oxide
Semiconductor):
battery powered non-volatile
chips used by the BIOS to store
date and time.
Video Card
Video Card Video cards are usually made up
of:
• a processing unit
• memory unit (usually RAM)
•a cooling mechanism
• connections to a display unit
Sound Card
Sound cards use two basic methods to translate
digital data into analogue signals needed for
speakers:
• FM synthesis mimics different musical
instruments according to built-in formulas
• wavetable synthesis relies on recordings of
actual instruments to produce sound
Software
•Programs that control computer systems
•Set of instructions that make computer do
something
•You cannot physically touch software
•Relates to ideas & instructions for using
physical objects
Two types of software:
•Application software:
• Programs that allow the user to do specific
task
• Design to carry out tasks
• Can be general purpose software or custommade software (specialist software)
• E.g. Spread sheets, databases, word
processing
Word processor is used to manipulate text documents.
• Spreadsheet is used to organise and manipulate numerical data.
• Database management system is used to organise, manipulate and analyse
data.
• Control and measuring software
• Apps (short for Applications) refers to the type of software that runs on
mobile phones or tablets.
• Photo editing software
• Video editing software
• Graphics manipulation software
System Software:
• Is Programs that allow the hardware to run
properly
• Control computer's hardware and application
program
• Communicate with user
• E.g. Operating system, device drivers, compiler
For example:
• Operating systems
• Utilities help to manage, maintain and control
computer resources. Examples:
o antivirus
o anti-spyware
o backup of files
o disk repair
o screensavers
• Device drivers allow hardware devices to
communicate with the operating system.
• Compiler translates a program written in highlevel language into machine code to be
understood by the computer.
• Linkers are used to put all the modules together
to form a final program.
Operating systems:
Tasks for a typical operating system:
control the operation of the input, output and backing
storage devices
supervising the loading, running and storage of application
programs
maintaining security of the whole computer system
maintaining a computer log (which details computer
usage)
allowing communication between the user and the
computer system (user interface)