A Diagrammatical Representation of the Computer
Central Processing Unit
Central
processing unit is the heart or brain of the computer. It consists of the
control unit, memory unit and the arithmetic logic unit (ALU). Its function is
to execute programs stored in the main memory by fetching their instruction,
examining them and then execute them one after another.
processing unit is the heart or brain of the computer. It consists of the
control unit, memory unit and the arithmetic logic unit (ALU). Its function is
to execute programs stored in the main memory by fetching their instruction,
examining them and then execute them one after another.
Control Unit
The
control unit directs supervises and co-ordinates all the activities of the
computer. The operation of the control unit is as follow:
control unit directs supervises and co-ordinates all the activities of the
computer. The operation of the control unit is as follow:
1)
Fetches in sequence the instructions the computer has been given
(stored)
Fetches in sequence the instructions the computer has been given
(stored)
2)
It interprets the instructions of the computer to the arithmetic logic
unit. (ALU)
It interprets the instructions of the computer to the arithmetic logic
unit. (ALU)
3)
It controls both input and output devices
It controls both input and output devices
4)
It initiate any appropriate action
It initiate any appropriate action
Arithmetic Logic Unit (ALU)
The
arithmetic and logic unit perform the arithmetic functions such as adding
subtracting, multiplying and division as well as the logic function such as
comparing two numbers.
arithmetic and logic unit perform the arithmetic functions such as adding
subtracting, multiplying and division as well as the logic function such as
comparing two numbers.
Main Memory Unit (Storage)
This
is part of the computer that provides a place to store date and instructions.
It is a storage place from where instructions are executed and therefore
normally the fastest storage unit of the computer i.e it is the working memory
of the computer. The main memory storage memory and it is commonly referred to
as RAM (Random Access Memory). The RAM holds the instruction and data that is
being worked on by the system at any time. RAM
is usually volatile i.e. whatever is stored in the RAM is lost when power is
lost from the computer.
is part of the computer that provides a place to store date and instructions.
It is a storage place from where instructions are executed and therefore
normally the fastest storage unit of the computer i.e it is the working memory
of the computer. The main memory storage memory and it is commonly referred to
as RAM (Random Access Memory). The RAM holds the instruction and data that is
being worked on by the system at any time. RAM
is usually volatile i.e. whatever is stored in the RAM is lost when power is
lost from the computer.
Read Only Memory (ROM)
It
is a special memory designed to store permanently the machine control sequence
or programs that directs the CPU. ROM is usually non-volatile memory that is
you will not loss its content when power is removed from the computer. It is
used only memory, therefore the user will not be able to access it or write
data into the ROM. ROM is usually coded by the computer manufacturer.
is a special memory designed to store permanently the machine control sequence
or programs that directs the CPU. ROM is usually non-volatile memory that is
you will not loss its content when power is removed from the computer. It is
used only memory, therefore the user will not be able to access it or write
data into the ROM. ROM is usually coded by the computer manufacturer.
The Backing or Auxiliary Storage Unit
The
backing storage or auxiliary storage unit are storage that are used fore
storing or keeping information permanently. Also backing storage keeps
voluminous information. Secondary storage also helps to make backup copy (extra
copy) of our information.
backing storage or auxiliary storage unit are storage that are used fore
storing or keeping information permanently. Also backing storage keeps
voluminous information. Secondary storage also helps to make backup copy (extra
copy) of our information.
The secondary storage is largely of two kinds
namely:
namely:
Direct
access storage devises like disks or diskettes sequential access storage device
like tapes.
access storage devises like disks or diskettes sequential access storage device
like tapes.
Access Time: This is the time in which data are transferred from
the placed where are stored to the time at which the transfer is completed.
the placed where are stored to the time at which the transfer is completed.
Basic Elements or Components of Computer
What is a Computer System?
A
computer system has no intelligence and is referred to as Hardware. A computer
system doesn’t come to life until it is connected to other parts of the system.
A computer system is a combination
of our elements:
computer system has no intelligence and is referred to as Hardware. A computer
system doesn’t come to life until it is connected to other parts of the system.
A computer system is a combination
of our elements:
A computer is a system that has a sub-system. Thus,
a computer functions. It consists of five major parts namely:
a computer functions. It consists of five major parts namely:
1.
Hardware
Hardware
2.
Software
Software
3.
Human ware / people ware
Human ware / people ware
4.
Procedure procedures
Procedure procedures
5.
Data / Information
Data / Information
When one computer is set up to communicate with
another computer system. Connectively becomes a sixth system element. In other
words, the manner in which the various individuals system are connected for
example, by phone line microwave transmission, or satellite is an element of
the total computer system.
another computer system. Connectively becomes a sixth system element. In other
words, the manner in which the various individuals system are connected for
example, by phone line microwave transmission, or satellite is an element of
the total computer system.
Hardware: This refers to those physical components of the
computer that can be seen and touched e.g. hard disk, monitor, keyboard, mouse
etc. OR Hardware: are the visible components of the computer
system.
computer that can be seen and touched e.g. hard disk, monitor, keyboard, mouse
etc. OR Hardware: are the visible components of the computer
system.
Software: Is the term used to describe the instructions
that the hardware haw to perform a
task. Without software instructions the
hardware doesn’t know what to do.
that the hardware haw to perform a
task. Without software instructions the
hardware doesn’t know what to do.
People: However,
constitute the most important component of the computer system. People operate
the computer hardware; they create computer software instructions and respond to
the Procedures that hose
instructions present.
constitute the most important component of the computer system. People operate
the computer hardware; they create computer software instructions and respond to
the Procedures that hose
instructions present.
The purpose of a computer system is to convert data
into information. Data are raw facts
and figure, concepts or instructions. These raw materials are processed into
useful information. This is to say information is product of data processing. Processing includes refining, summarizing,
categorizing and otherwise manipulating the data into a useful form for
decision-making.
into information. Data are raw facts
and figure, concepts or instructions. These raw materials are processed into
useful information. This is to say information is product of data processing. Processing includes refining, summarizing,
categorizing and otherwise manipulating the data into a useful form for
decision-making.
