Types and components of computer systems

1. Chapter 1
Types and Components of Computer Systems

2. Objectives
 Define hardware, giving examples
 Define software, giving examples
 Describe the difference between hardware and software
 Identify the main components of a general-purpose computer: central processing
unit, main/internal memory (including ROM and RAM), input devices, output
devices and secondary/backing storage
 Identify operating systems, including those which contain a graphical user
interface, a command line interface
 Identify different types of computer including Personal Computer or desktop,
mainframe, laptop, palmtop and Personal Digital Assistant
 Describe recent developments in ICT

3. 1.1
Hardware Vs Software

4. Hardware
 "All the physical parts of a
computer that you you can
see, touch and pick up.

5. Internal and external Hardware
 Internal Hardware Devices:
 Central processing unit
 Processor
 Motherboard
 Internal memory consisting of RAM & ROM
 Graphics & Sound Cards
 Internal Storage devices like Hard disk drives (HDD)and solid-state drives (SSD)
 Network interface card (NIC)
 External Hardware Devices:
 Monitor
 Keyboard
 Mouse
 Printer
 External Storage Devices

6. Hardware components: inside the case
 The computer case contains the
motherboard on which other
components are mounted, such as
the CPU, the main memory and
expansion slots for other hardware
components, and the internal hard
disk drive.
 Sound card, a video card and a
cooling mechanism, such as a fan.

8. Software
 Coded programs that control how the computer works“
 Software cannot be touched or picked up.
 There are 2 types of software - System Software and Application Software.
 It refers to the programs that we run on our computer and it tells the
hardware how to do something useful.
 Without software, most hardware would be useless.

9. Types of software
Applications software provides the services that the user
requires to solve a task
Examples of applications software including word
processing, spreadsheet, database management systems,
control, measurement, applets and apps, video editing,
graphics editing, audio editing, computer aided design
(CAD)
System software provides the services that the computer
requires to operate
Examples of system software including compilers, linkers,
device drivers, operating systems and utilities

10. System Software
 Compilers: The software translates the High-level language into Machine code (Language
Machine code (Language Processor).
 Linkers: A Software that creates the links between Language processors into workable
processors into workable solutions (Data definition language).
 Device drivers: A software that enables the device to work with another, externally
another, externally connected device.
 Utilities: A system software that provides the necessary facilities (Antivirus, Scan Disk,
(Antivirus, Scan Disk, Disk Defragmentation, etc.)
 Operating systems: To enable computer systems to function and allow users to
allow users to communicate with computer systems

12. Analogue and Digital Data
 Computers can only understand data in the form of binary digits (0,1); this is commonly known as digital data.
However, data in the real world is analogue, not limited to two specific values.
 So, for a computer to process real-world data, it firstneeds to convert the received data into digital form. Thisis done
by hardware known as ADC (analogue to digitalconverter), and its output is given back in analogue formusing DAC
(digital to analogue converter).

13. 1.2
The Main Components of
Computer Systems

14. Central Processing Unit (CPU)
 The component of the computer that understands and executes hardware
and software operations. Nowadays, it’s also known as a microprocessor. It
is a single integrated circuit at the core of most PCs and is also present in
many household gadgets and equipment where some control or monitoring
is required.
 It consists of a control unit (CU) that manages the input and output devices,
an arithmetic and logic unit (ALU) that performs computations and makes
logical judgments, and tiny memory regions known as registers.
 It processes the input and produces the outcome of the processing in the
form of output.

15. Internal Memory
 Random access memory (RAM): temporary memory storage, lost after power is
lost after power is shut down, performs read and write functions, is used to store
data that are currently in use, and can be increased in size to improve operational
speed.
 Read-only memory (ROM): permanent memory storage, non-volatile, can only be
volatile, can only be read from, used to store computer’s configuration data, such
as BIOS.

16. Differentiating between Internal memories:
RAM is a temporary memory device, whereas ROM isa permanent one.
RAM is volatile, ROM is non-volatile.
RAM can be written to and from, but ROM can only be read from.
RAM is used to store data, files, programs, and parts of OS that are currently in
use. However, ROM is used in storing start-up data,

17. Input & Output
Devices

18. Backing and Secondary Storage
 Required to store significant amounts of data permanently.
 Most commonly in the form of Hard disk drives and Solid-state drives.
Differentiating between internal memory and backing storage:
 RAM contents are lost when power is lost, ROM is read-only, and backing storage is permanent even without power.
 RAM and ROM are much smaller than backing storage.
 RAM and ROM are significantly faster in accessing data than backing storage.
 Backing storage is much cheaper than internal memory.
 Internal memories are fixed, and backing storage can be fixed or portable.
 Internal memories can be directly read by the CPU, while backing storage needs to be moved into the RAM before being
read by the CPU

19. 1.3.
Operating Systems

20. Operating Systems
 Controls operation of input, output & backing storage
 Supervises loading, running & storage of application programs.
 Deals with errors in application programs.
 Maintains security of the whole computer system
 Maintains a computer log.

21. Operating systems user interfaces
 Command line interface: user needs to type in commands to communicate with the computer : possible to alter computer
computer : possible to alter computer configuration settings. Needs to learn many commands for basic operations. All
commands need to be typed in, which is time-consuming. Very error prone, as commands must have correct format,
spelling etc.
 Graphical user interface: (GPU) Uses WIMP (windows icons menu and pointing device). The user does not need to learn
user does not need to learn any commands. It is more user-friendly; icons are used to represent applications. A pointing
devices used to click on an icon to launch the application ,this is simpler than typing in commands. This type of interface
uses up considerably more computer memory than a CLI interface. The user is limited to the icons provided on the screen.
Needs a more complex operating system.

22. Operating systems user interfaces
 Dialogue-based user interface: use the human voice to give commands to a computer system. no need for a driver
system. no need for a driver to take their hands off the steering wheel. In a home, it is especially useful for people with
disabilities because many tasks can be carried out by the spoken word only. Possible to use it as a security feature
because voice recognition could be used to identify a person. Still unreliable, with many commands not being
recognized or needing to be repeated several times (especially if there is background noise). Can be quite complex to
setup. User needs to know which commands can be used.
 Gesture-based user interface: relies on human interaction by the moving of hands, head or even feet. Replaces
or even feet. Replaces mechanical input devices. No physical contact is required. Very natural interface for a human
operator. No training is needed to interface with the computer. It is possible for unintentional movement to be picked
up. Only works near the camera or sensor(maximum of 1.5 meters). May only accept a limited number of movements
(for example, it may take several attempts to determine exactly

23. 1.4
Types of Computers

24. Types of Computers
 Definition of a Computer:
"Computers are devices that accept information and then manipulate it
to produce a result.
 Personal Computer
 Laptop
 Tablets
 Mainframe
 Notebook
 Smartphones

25. Types of Computers

26. Mainframes Computers
 Mainframes are very large and expensive and are capable of
supporting hundreds, or even thousands, of users at the
same time.
 They are used in large organizations for processing huge
amounts of data or to control massive networks of
computers.
 Mainframes use more than one processor (parallel
processing) which means they can process many jobs at the
same time.
 Early mainframes were the size of a room and got their
name because they were housed in large metal ‘frames’.

27. 1.5.
Impact of Emerging
Technologies

28. Artificial Intelligence (AI)
 AI is a machine or application which carries out a task that requires some degree of intelligence. Examples:
 recognizing a person’s face
 the ability to operate machinery, such as a car, aero plane, train, and so on,
 analyzing data to predict the outcome of a future event, for example, weather forecasting
 An autonomous (driverless) vehicle

29. Artificial Intelligence (AI)
Advantages:
 Increased Efficiency: AI and robots can perform tasks much faster and more
 Robots are used to help people carry out dangerous or unpleasant tasks –
 Improved Healthcare: AI can assist doctors in diagnosing diseases more
leading to improved healthcare outcomes. Surgical robots
Negative Impacts:
 Job Displacement: Automation through AI and robots can lead to job losses in
certain industries,
 Dependency and Overreliance: Overreliance on AI and robots can lead to a loss of
human skills and capabilities
 Privacy Concerns: The widespread adoption of AI technologies raises concerns
about privacy, as these systems often collect and analyze large amounts of personal
data

30. Extended reality
 Augmented reality (AR) is a merger between the virtual and physical (real) world; it lays objects onto pre-existing objects.
objects onto pre-existing objects. e.g., Pokémon GO!
 Impact: safety and rescue operations’ training, shopping and retail(getting a better look at a car before the
purchase),healthcare (better understanding of a patient’s body)
 Virtual reality (VR) enables an entirely new world to be created, unlike AR, which has no link to the actual surroundings of
to the actual surroundings of the user. It requires the user to be specially equipped with a VR headset, joystick, and
headphones.
 Impact: Military applications, educational purposes (looking at ancient buildings), healthcare, media
(interactive special effects in a movie), scientific visualization (part of molecular structures/cells).