Thursday 8 th October, 2015 Information Technology Fundamentals of Hardware & Software

Thursday 8th October, 2015

Information Technology

Fundamentals of Hardware & Software


At the end of this lesson you will be able to:

Explain functions of RAM and ROM

Classify differences between RAM and ROM.


At the end of this lesson you will be able to:

Identify units of storage Convert bytes to Kilobytes, KB, Megabytes, MB and Gigabytes, GB


The Digital Computer (Bits and Bytes, Episode 1)

https://www.youtube.com/watch?v=AdF2uk-EscE


Primary Storage

There are two types of main memory or primary storage:-

Random Access Memory, RAM

ROM, Read Only Memory

Random Access Memory, RAMFunctions of RAM:- The data in RAM can be read (retrieved)

or written (stored) It stores data that can be accessed

directly by the processor Holds temporary instructions or volatile

data needed to complete tasks Holds data during and after processing Contents are modified by programs

Read Only Memory, ROM

Functions of ROM:- The data in ROM cannot be changed,

therefore it can only be read (retrieved). Stores all programs and data when

turned off. It is non-volatile. Contains many complex functions such

as start up operating instructions Contents of ROM are usually

programmed by manufacturer

Comparison between RAM and ROM chips

RAM ROM

Read, Write

Volatile, Non-Volatile

Contents

Comparison between RAM and Rom

RAM ROM

Read, Write Read and Write Read

Volatile, Non-Volatile

Volatile Non-Volatile

Contents Contents can be

modifiedContents cannot be modified

Data Types and Their Representations

Communicator Data Type/Storage

Humans Letters

Humans Numbers

Humans Words


Communicator Data Type/Storage

Computer Bits

Computer Bytes

Computer Words


Bit –Bit is a combination of the words Binary

Digit.Generally in computers, information is stored in the form of electrical pulses or signals. They are of two states, ‘On’ or ‘Off’ and are represented by 1 and 0, Binary Digits, respectively.


Bit Pattern –

The sequence in which Bits are placed to represent a character. An example is

101101012

= 18110


Byte –

A Byte is comprised of 8 bits and is used to represent a character such as

A letter e.g. A, B, or Y A digit e.g. 1,2 or 4 A special symbol e.g. @, (, ), $


Word –

A Word is the number of bits that can be processed at any one time.


Wordsize or Word Length –

The number of bits that a computer can process or store as a unit. For example some PCs have been labelled as 32-bit or 64-bit machines according to their wordsize. This means that a 32-bit machine can process 32-bits in a less than a millionth of a second.


Conversion of Bits to Bytes and Bytes to KB, MB, GB and TB

8 bits = 1 Byte

1024 Bytes = 1 KB (KiloByte)

1024 KB = 1 MB (MegaByte)

1024 MB = 1 GB (GigaByte)

1024 GB = 1TB (TeraByte)



Evaluation

1. How is a bit different from a byte?

2. Which two digits are associated with bits?

3. Convert the following:-a. 100 KB = Bytes

b. 1.52 TB = MB

c. 4.541GB = KB

d. 35600 KB = MB

Evaluation

4. How is a bit different from a byte?

5. Which two digits are associated with bits?

6. Convert the following:-a. 100 KB = Bytes

b. 1.52 TB = MB

c. 4.541GB = KB

d. 35600 KB = MB

Evaluation1. How is a bit different from a byte?

Ans. - Byte has 8 bits, therefore it is larger.

2. Which two digits are associated with bits? 1, 0

3. Convert the following:-a. 100 KB = 102400 Bytes

b. 1.52 TB = 1593835.25 MB

c. 4.541GB = 4761583.616 KB

d. 35600 KB = 34.765625 MB


Recap:-

Today we learnt Explain functions of RAM and ROM Classify differences between RAM and

ROM Identify units of storage Convert bytes to Kilobytes, KB,

Megabytes, MB and Gigabytes, GB

Thank you for being a great class and have a good afternoon!

Please check google drive for today’s lesson.

Documents

Thursday 8 th October, 2015 Information Technology Fundamentals of Hardware & Software