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3. Device drivers: A software that enables the

device to work with another, externally
1. ## 1.1. THEORY connected device.
4. Utilities: A system software that provides the
necessary facilities, (Antivirus, Scan Disk, Disk
Types and Components of Defragmentation etc.)
5. Operating systems: enable computer systems
Computer Systems to function and allow users to communicate
with computer systems, special software,
Hardware & Software known as operating systems (OS), have been
developed.
Hardware
Analogue and digital data
the electronic physical components that make up a typical
computer system. These may include input and output
Computers can only understand data in the form of binary
devices as well.
digits (0,1), this is commonly known as digital data. However,
Internal Hardware Devices:
data in the real world is analogue, it isn’t limited to two
Central processing unit
specific values.
Processor
Motherboard
Internal memory consisting of; RAM & ROM
Graphics & Sound Cards
Internal Storage devices like Hard disk drive (HDD) &
Solid-state drive (SSD)
Network interface card (NIC)
External Hardware Devices:
Monitor
Keyboard
Mouse
Printer
External Storage Devices

Software

The techniques, methods, commands, and instructions,

which tell the device what to do and how to do it. They are
the programs that control the computer system and
process data. The figures show how data changes in analogue and digital
Relates to ideas & instructions for using physical objects. forms, analogue data forms smooth curves whereas digital
data changes in discrete steps.
Two types of software:
So, for a computer to be able to process real-world data, it
Application software: first needs to convert the received data into digital form. This
Provides services that allow the user to do specific is done by hardware known as ADC (analogue to digital
tasks. converter), and its output is given back in analogue form
Can be general purpose software or custom-made using DAC (digital to analogue converter).
software. (Specialist software)
E.g., Spread sheets, databases, word processing. 1.2. The Main Components of Computer
System Software:
The software designed to provide a platform on which
Systems
all other software can run. For example:
1. Compilers: The software used to translate the Central Processing Unit (CPU)
High-level language into Machine code
(Language Processor). The component of the computer that understands and
2. Linkers: A Software that creates the links executes hardware and software operations. Nowadays,
it’s also known as a microprocessor. It is a single
between Language processors into workable
integrated circuit that is at the core of most PCs and is
solutions (Data definition language).
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also present in many household gadgets and equipment Input devices Output devices
where some control or monitoring is required. Input devices are complex as
It consists of a control unit (CU) that manages the input Output devices are simpler as
they need to ensure proper
and output devices, an arithmetic and logic unit (ALU) that they only need to display the
communication between
performs computations and makes logical judgments, and finale.
computer and user.
tiny memory regions known as registers.
It processes the input and produces the outcome of the
processing in the form of output.
Backing/Secondary Storage

Internal Memory Required to permanently store significant amounts of

data.
1. Random access memory (RAM): temporary memory Most commonly in form of Hard disk drives and Solid-
storage, lost after power is shut down, performs read state drives.
and write functions, used to store data that’s currently
Differentiating between internal memory and backing
in use, can be increased in size to improve operational
storage:
speed.
2. Read only memory (ROM): permanent memory 1. RAM contents are lost when power is lost, and ROM is
storage, non-volatile, can only be read from, used to read-only, backing storage is permanent even without
store computer’s configuration data, such as BIOS. power.
2. RAM and ROM are much smaller as compared to
N.B: The BIOS (basic input/output
backing storage.
system) stores the date, time and
3. RAM and ROM are significantly faster in accessing
system configuration on a non-volatile
data as compared to backing storage.
chip called a CMOS (complementary
4. Backing storage is much cheaper than internal
metal oxide semiconductor) – this is
memory.
usually battery powered.
5. Internal memories are fixed, backing storage can be
Differentiating between Internal memories: fixed or portable.
6. Internal memories can be directly read by the CPU,
1. RAM is temporary memory device, whereas ROM is while backing storage needs to be moved into the
permanent memory device. RAM before being read by the CPU.
2. RAM is volatile, ROM is non-volatile.
3. RAM can be written to and read from, but ROM can 1.3. Operating Systems
only be read from.
4. RAM is used to store data, files, programs and parts of Controls operation of input, output & backing storage
OS in current use. However, ROM is used in storing Supervises loading, running & storage of application
start-up data. program.
Deals with error in application programs.
Maintains security of whole computer system
Input & Output Devices
Maintains a computer log.
Input devices are pieces of hardware that allow users to Operating systems offer various types of user interfaces, for
enter data into computers. example:
An output device displays the computer's output in a
human-readable format. As words on a printer, for 1. Command line interface: user needs to type in
example, or moving graphics on a monitor. commands to communicate with the computer. The
user is in direct communication with the computer.
Input devices Output devices Not restricted to pre-defined options. Possible to alter
An input device is any An output shows the result or computer configuration settings. Needs to learn many
hardware that enables data solution of the input after it commands for basic operations. All commands need
entry. has been processed. to be typed in, time-consuming. Very error prone, as
An input device can only send An output device can only commands must have correct format, spelling etc.
data. receive data. N.B: Mainly used by programmers who need to have
direct communication with the computer.
Input devices are necessary Output devices are needed in
2. Graphical user interface: Uses WIMP (windows icons
for a computer to receive order to display the outcome
menu and pointing device). The user does not need to
commands from the user for of the processing that took
learn any commands. It is more user-friendly; icons
processing to be permitted. place to the user.
are used to represent applications. A pointing device
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is used to click on an icon to launch the application, 6. as they usually have wired connections, they have
this is simpler than typing in commands. This type of more stable internet access.
interface uses up considerably more computer Disadvantages:
memory than a CLI interface. The user is limited to the 1. not particularly portable because they are made
icons provided on the screen. Needs a more complex up of separate components.
operating system. 2. More complicated because all the components
N.B: Mainly used by end-users who don’t have great need to be hooked up by wiring, which also clutters
knowledge of how the computer works. up the desk space.
3. Dialogue-based user interface: use the human voice 3. Because they aren’t portable, files need to be
to give commands to a computer system. no need for copied to another portable storage device to take
a driver to take their hands off the steering wheel. In a work elsewhere.
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 Mobile Computers:
because voice recognition could be used to identify a
person. Still unreliable, with many commands not 1. Laptop computer:
being recognized or needing to be repeated several
times (especially if there is background noise). Can be (Or notebook) refers to a type of computer where the
quite complex to setup. User needs to know which monitor, keyboard, pointing device and processor are all
commands can be used. together in one single unit. This makes them extremely
4. Gesture-based user interface: rely on human portable. lightweight (to aid portability). Low power
interaction by the moving of hands, head or even the consumption (and also long battery life). Low heat output
feet. Replaces mechanical input devices. No physical (cooling is very important).
contact required. Very natural interface for a human Uses:
operator. No training needed to interface with the 1. office and business work
computer. Possible for unintentional movement to be 2. educational use
3. used as a gaming device.
picked up. Only works near to the camera or sensor
4. general entertainment
(maximum of 1.5 meters). May only accept a limited
number of movements (for example, it may take Advantages:
several attempts to find out exactly what finger 1. Portability, all components are in a single unit so
movements are recognized). that they can be taken anywhere.
2. because of one single unit, there are no trailing
wires, and desk cluttering.
1.4. Types of Computers 3. take up much less room on a desk, so they can be
easily used in public spaces.
Desktop Computers 4. portability allows them to take full advantage of
Wi-Fi features.
Desktop usually refers to a general-purpose computer
Disadvantages:
that is made up of a separate monitor, keyboard, mouse,
1. portability makes it easier for them to be stolen.
and processor unit. It is distinguished from, for example, a
2. limited battery life means user needs to carry
laptop computer by the fact that it is made up of several
charger at all times.
separate components, which makes it not very portable. 3. keyboards and pointing devices may be awkward
Uses:
to use.
1. office and business work
4. not easy to upgrade, like adding more RAM.
2. educational use
3. general entertainment 2. Smartphones:
4. gaming device
Advantages: Allow normal phone calls to be made, but also have an
1. they are easier and less costly to upgrade and operating system (such as iOS, Android, or Windows)
expand. allowing them to run a number of computer applications
2. spare parts are standardized, which makes them (known as apps or applets). Smartphones communicate
cheaper. with the internet either by using Wi-Fi hot spots or by
3. they tend to have better specifications for a given using 3G/4G/5G mobile phone networks.
price. Uses:
4. no critical power consumption because they plug 1. They allow users to send/receive emails.
into a wall socket. 2. They allow users to use a number of apps.
5. due to fixed position, they are less likely to be 3. They allow users to use a camera feature (to take
damaged or stolen. photos or videos).
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4. They allow users to use a MP3/4 player (for music 3. typing on a touch screen can be slow and error
and videos). prone compared to a standard keyboard.
Advantages: 4. laptops tend to support more file formats than
1. very small in size and lightweight, makes them tablets.
portable.
2. connecting to the internet while on the move. 4. Phablets:
3. because they use Wi-Fi and mobile phone
networks, they can be used almost anywhere. Some of the latest smartphones have been designed as a
4. they have apps which can tell instant location, hybrid between a tablet and a smartphone; these are
which is a feature that isn’t available in either referred to as a phablet. They have much larger screens
desktops or laptops. than a smartphone but are smaller than a tablet.
5. they have reasonable battery life.
Disadvantages:
1. small screens and keyboards make pages difficult
to read.
2. more difficult and slower when typing things in.
3. Web browsing and photography can quickly drain
the battery.
4. Memory size in most phones is not very large
when compared to laptops and desktops.
5. Not all website features are compatible with
smartphone operating systems.
6. Because of their small size, it is much easier to
lose a smartphone or for it to be stolen compared
to laptops or desktops. Uses:
7. The data transfer rate using mobile phone 1. Entertainment (streaming of music, videos, and
networks can be slower than with Wi-Fi. television programs).
2. Gaming (including group games).
3. Tablets: 3. As a camera or video camera.
4. Internet use (online sales, social networks, using
They work similarly to a smartphone. The only main QR codes, and so on).
difference is that they are much somewhat bigger in size 5. Sending/receiving emails.
as compared to a smartphone. 6. Global positioning system (use of maps to navigate
Uses: to a location).
1. They allow users to send/receive emails. 7. Calendar functions.
2. They allow users to use a number of apps. 8. Telephone banking (sending and receiving money
3. They allow users to use a camera feature (to take using banking apps).
photos or videos). 9. Voice over Internet Protocol: telephone network
4. They allow users to use a MP3/4 player (for music using the internet, which also allows video calling.
and videos). 10. Instant access to social networks (social contact
Advantages of tablets compared to laptops: with friends no matter where you are in the world).
1. very fast to switch on (no time delay waiting for the 11. Instant messaging.
operating system to load up). 12. Office and business management (allows rapid
2. fully portable – they are so lightweight that they voice and video communication).
can be carried anywhere. 13. Education use (using interactive software to teach
3. touch screen technology means they are simple to or learn from).
use and don’t need any other input devices. 14. Remotely control devices.
4. not much heat, they use solid-state technology. Laptops are the most expandable of these devices,
5. battery life of a tablet is a lot longer. while smartphones are the most portable. Tablets
6. when the power button is pressed, it goes into and phablets fall somewhere in between, offering
standby, but remains connected to the internet so a balance of portability and expandability. The
the user still hears alerts when emails or other choice of which device to use will depend on your
‘events’ are received. specific needs and use case.
Disadvantages of tablets compared to laptops:
1. tend to be rather expensive when compared to
1.5. Impact of Emerging Technologies
laptops.
2. they often have limited memory/storage when Artificial Intelligence (AI): There are many definitions of
compared to a laptop. artificial intelligence (AI). Essentially, AI is a machine or
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application which carries out a task that requires some An input device can send data to another device, but it
degree of intelligence. – the use of language, – cannot receive data from another device.
recognizing a person’s face, – the ability to operate Input devices are necessary for a computer to receive
machinery, such as a car, airplane, train, and so on, – commands from its users and data to process; the
analyzing data to predict the outcome of a future event, devices are under the control of the user or can be direct
for example weather forecasting. Impact: Whenever AI is data entry.
mentioned, people usually think of science fiction
fantasies and think of robots. The science fiction writer Input devices can be complicated because they must ensure
Isaac Asimov even went as far as producing his three laws that the user can interact with the computer correctly.
of robotics: » Robots may not injure a human through
action or inaction. » Robots must obey order given by 1. Keyboards:
humans without question. » A robot must protect itself
Uses:
unless it conflicts with the two laws above. Everyday uses:
1. An autonomous (driverless) vehicle – we already Input of data into applications software
have driverless trains and autopilots on airplanes, Typing in commands to the computer
but future developments include driverless cars.
2. Robotic research is leading to improvements in Advantages:
technology to help amputees and people with
disabilities. Fast entry of new text into a document.
3. Robots are used to help people carry out Well-known method.
dangerous or unpleasant tasks – for example, Easy to use for most people.
bomb disposal, Negative impacts of AI: Easier to do verification checks as data is entered (can
immediately compare the source document with typed
4. Unemployment, robots are capable of doing
tedious human tasks with much more efficiency data on the screen).
and excellence than humans.
Disadvantages:
5. Dependency on technology could lead to problems
in the future. Can be difficult to use if the user has limited arm/wrist
6. De-skilling: tasks that used to be considered a use.
talent are now part of general, tedious processes Slow method when compared to direct data entry.
that are done on a regular process by machines. Fairly large device that uses up valuable desk space.
Extended reality: refers to real and virtual combined
environments. The two most common examples at the
moment are: » Augmented reality (AR) is a merger
between the virtual and physical (real) world, it lays
objects onto the 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, this has no link to the actual 2. Numeric keypads:
surroundings of the user. It requires the user to be
specially equipped with a VR headset, joystick, and Uses:
headphones. Impact: Military applications, educational
purposes (looking at ancient buildings), healthcare, media Automatic teller machines (ATMs), where the customer
(interactive special effects in a movie), scientific can key in their PIN, amount of money, etc.
visualization (part of molecular structures/cells). Mobile phones to allow phone numbers, etc. to be keyed
in.
Point of sale terminals (POS) in case the barcode reader
2. ## 2.1. THEORY fails to read the barcode – the number has to be keyed in
manually by the operator.
Chip and PIN devices when paying by credit/debit cards.
Input & Output Devices Fast entry of numeric data into a spreadsheet.

Advantages:
Input Devices & their Uses
Faster than standard keyboards when entering numeric
An input device is any hardware device that allows a user data.
to enter data or instructions into a computer directly.