COMPUTER HARDWARE
By
Meeme Julius M’Lingera (EMELISWAP)
(Email: )
Dated: July, 2021
Target Student/Trainees
Everyone taking any unit in Computer Literacy, Computer Studies,
Computer Science or Information and Communication Technology
(ICT) and other related subjects in either
Secondary or Tertiary Level
For Additional Information
You can contact the author through the email: for additional information
Page 1 of 18
,Functional Organization of a Computer
- A computer is made up of a collection of different components that are interconnected
together in order to function as a single entity.
- A computer system – this is a collection of independent entities or components that
collectively work together to process and manage information using computers in order to
accomplish a specific goal as required by the user. The three main components (elements) of
a computer system are: Hardware, Software and Liveware.
- Computer hardware are all the physical and tangible electronic, mechanical and
electromechanical components of a computer system.
- But computer hardware is classified into two categories (parts) which are: system unit and
the peripherals
a) A system unit is the box that houses the heart (brain) of the computer called
Central Processing Unit) and drives that store, record and read data.
b) Peripherals are all the devices that are connected to the system unit through the
ports. They include: input devices, output devices, communication devices and
external secondary storage devices
Assignment:
a) Draw a well labelled diagram illustrating the various external basic parts of a computer
b) Download images for various computer hardware devices
- Generally, all types of computers follow the same basic logical structure and perform the
following five basic functions (operations) for converting raw input data into information
useful to their users. These functions are as follows: taking input, storing data, processing
data, outputting information and controlling workflow
- Based on the above functions of a computer, there are four major components (categories) of
computer hardware. These are: input devices, processing devices, storage devices and output
devices.
- The following is thus a diagram illustrating the functional organization of the computer
hardware based on the above five functions that it performs :
Page 2 of 18
, Input unit Storage Output unit
Control Unit
Arithmetic & CPU
Logic Unit
Key: the arrowed dotted lines indicates the flow of instructions, while the arrowed solid lines
indicates the flow of data and/or information
Computer Input devices
- Input devices are the devices which are used for getting data or instructions from the
external environment, accepting it and entering it into the CPU for processing.
- The two types of Input devices are:
a. Keyboard entry (Keying devices)
b. Direct entry.
a) Keying devices
- These are the devices used for entering data into the CPU through typing with the use of
keys. The two main devices used are the keypad and the keyboard
i) Keypad
- This is a miniature (tiny) keyboard which is mostly used on small portable computers,
calculators, palm notes and mobile phones.
ii) Keyboard
- This is an input device used for entering data into the computer by pressing and
releasing its various keys.
- The keys in the keyboard can be categorized into five parts (groups). These are:
Page 3 of 18
By
Meeme Julius M’Lingera (EMELISWAP)
(Email: )
Dated: July, 2021
Target Student/Trainees
Everyone taking any unit in Computer Literacy, Computer Studies,
Computer Science or Information and Communication Technology
(ICT) and other related subjects in either
Secondary or Tertiary Level
For Additional Information
You can contact the author through the email: for additional information
Page 1 of 18
,Functional Organization of a Computer
- A computer is made up of a collection of different components that are interconnected
together in order to function as a single entity.
- A computer system – this is a collection of independent entities or components that
collectively work together to process and manage information using computers in order to
accomplish a specific goal as required by the user. The three main components (elements) of
a computer system are: Hardware, Software and Liveware.
- Computer hardware are all the physical and tangible electronic, mechanical and
electromechanical components of a computer system.
- But computer hardware is classified into two categories (parts) which are: system unit and
the peripherals
a) A system unit is the box that houses the heart (brain) of the computer called
Central Processing Unit) and drives that store, record and read data.
b) Peripherals are all the devices that are connected to the system unit through the
ports. They include: input devices, output devices, communication devices and
external secondary storage devices
Assignment:
a) Draw a well labelled diagram illustrating the various external basic parts of a computer
b) Download images for various computer hardware devices
- Generally, all types of computers follow the same basic logical structure and perform the
following five basic functions (operations) for converting raw input data into information
useful to their users. These functions are as follows: taking input, storing data, processing
data, outputting information and controlling workflow
- Based on the above functions of a computer, there are four major components (categories) of
computer hardware. These are: input devices, processing devices, storage devices and output
devices.
- The following is thus a diagram illustrating the functional organization of the computer
hardware based on the above five functions that it performs :
Page 2 of 18
, Input unit Storage Output unit
Control Unit
Arithmetic & CPU
Logic Unit
Key: the arrowed dotted lines indicates the flow of instructions, while the arrowed solid lines
indicates the flow of data and/or information
Computer Input devices
- Input devices are the devices which are used for getting data or instructions from the
external environment, accepting it and entering it into the CPU for processing.
- The two types of Input devices are:
a. Keyboard entry (Keying devices)
b. Direct entry.
a) Keying devices
- These are the devices used for entering data into the CPU through typing with the use of
keys. The two main devices used are the keypad and the keyboard
i) Keypad
- This is a miniature (tiny) keyboard which is mostly used on small portable computers,
calculators, palm notes and mobile phones.
ii) Keyboard
- This is an input device used for entering data into the computer by pressing and
releasing its various keys.
- The keys in the keyboard can be categorized into five parts (groups). These are:
Page 3 of 18
