unit 1 computer operations and fundamentals lesson … · cache memory 3 types of primary storage...
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UNIT 1
COMPUTER OPERATIONS AND
FUNDAMENTALS
LESSON 4:
Primary and secondary storage
Primary Storage
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Primary storage refers to memory that
is directly accessible to the CPU.
It is also known as internal memory or
main memory.
Primary Storage
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The CPU continuously reads the instructions
stored in primary storage and executes them as
required.
Central Processing
Unit
Primary storage
Types of Primary Storage
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Primary Storage
Read Only Memory (ROM)
Random Access Memory (RAM)
Cache Memory
3 Types of Primary Storage are:
Read Only Memory (ROM)
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• ROM is non-volatile memory.
▪ This means that Information in ROM
is stored permanently.
• This is done during the manufacture of
the chip.
• ROM stores instructions that are
required to start the computer.
Random Access Memory (RAM)
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•RAM is volatile memory.
•This means that, it loses its
contents when the computer is
switched off.
• It stores programs and files
currently being used by the CPU.
Cache Memory
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•Cache memory is high speed memory.
•The CPU can access cache memory more
quickly than it can access RAM.
Cache Memory
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• It increases the performance of the CPU.
• It stores frequently used instructions so that
they are immediately available to the CPU
when needed.
Secondary Storage
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Secondary storage refers to storage that is not
directly accessible by the CPU.
Secondary Storage is also called
• External memory
• Secondary memory
• Auxiliary storage
Secondary Storage
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•Secondary storage is used to store files
when the computer is switched off.
•Programs and files are stored until they are
overwritten or deleted by the user.
Secondary Storage
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Examples of secondary storage:
• hard disks
• optical discs
• pen drives
• memory cards
Differences between Primary and Secondary Storage
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• Primary storage is directly accessible by the CPU
whereas secondary storage is not directly
accessible by the CPU.
• Accessing primary storage is faster than accessing
secondary storage.
• Secondary storage can be removed from one
computer and used with other computers.
Quick Test
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1. Another name for Internal memory is______.
A primary storage
B secondary storage
C auxiliary storage
Quick Test
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1. Another name for Internal memory is______.
A primary storage
B secondary storage
C auxiliary storage
Answer A
Internal memory is also known as Primary storage
Quick Test
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TRUE FALSE
2. RAM stores files permanently.
Quick Test
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FALSE
RAM loses its contents when the computer is
switched off.
Therefore it is not permanent
2. RAM stores files permanently.
Quick Test
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TRUE FALSE
stored in
3. Information stored in ROM cannot be deleted.
Quick Test
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TRUE
Information is permanently stored in ROM
during manufacture.
Therefore it cannot be deleted.
3. Information stored in ROM cannot be deleted.
Quick Test
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TRUE FALSE
The CPU can access cache memory
4. RAM provides faster access than cache memory.
Quick Test
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FALSE
The CPU can access cache memory more quickly
than it can access RAM.
Therefore RAM is not faster than cache memory.
Answer FALSE
4. RAM provides faster access than cache memory.
Quick Test
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TRUE FALSE
5. Secondary storage stores files permanently.
Quick Test
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TRUE
Secondary storage stores files until they are overwritten or
deleted by the user.
Therefore data in secondary storage is not permanent
Answer FALSE
5. Secondary storage stores files permanently.
Recap
• Primary storage is memory which is directly
accessible by the CPU.
Primary storage
Main memory
Internal memory
Recap
Three Types of primary storage are
1.Read Only Memory (ROM)
2.Random Access Memory (RAM)
3.Cache Memory
Recap
Secondary storage is not directly accessible by the
CPU.
Some other names for secondary storage are:
1.External memory
2.Secondary memory
3.Auxiliary storage
Recap
Examples of secondary storage:
• hard disks
• optical discs
• pen drives
• memory cards
We will learn about secondary storage devices in the next lesson
End of Lesson