JSS 2 WEEK EIGHT LESSON NOTE (ICT_223)

 

Jss 2

Topic: UNIT OF STORAGE IN COMPUTER

Introduction

Computer memory is a storage location where data/information are kept or stored. The computer hard disk memory is referred to as the main memory and it is divided into two namely ROM (Read Only Memory) and RAM (Random Access Memory).

 Computer Units of Storage

Electronic computers understand and use 0s and 1s which are called binary codes or bits. Hence we have various units of storage in which Bit is the smallest of them. They are:

1.     Bit

2.     Nibble

3.     Byte

4.     Word

Bit: it is the first and smallest unit of memory, it uses 0s and 1s. bits are arranged in the strings of 0s and 1s e.g. 01001011

Nibble: it is a storage unit that is in a sequence of 4 bits i.e. it is equivalent to 4 bits. In essence 1 nibble = 4 bits e.g. 1010 = 1 nibble.

Byte: it is the smallest memory space in a computer and it is equivalent to 2 nibble or 8bits. e.g. 10110101 = 1 byte.

Word: it is made up of 2 bytes i.e. 4 nibble or 16bits e.g. 1010101011011101

Unit Conversion

1 nibble = 4 bits

2 bytes = 8bits

1 kilobytes (KB) = 1024bytes

1 megabytes (MB) = 1024KB

1 gigabytes (GB) = 1024 MB

1 terabyte (TB) = 1024 GB

1 petabyte (PB) = 1024 TB

A byte can be said to be the basic unit of a sequence of 8bits. Other higher memory units associated with bytes are:

kilobyte: 1000 bytes

megabyte: 100000 bytes

gigabyte: 1000000000 bytes

The hard disk of computers is measured in kilobytes, megabytes and gigabytes. 



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