Computer Notes a Level-Paper 1
Components of a Computer System and Modes of Use
Chapter 1.1 Hardware and Software Definitions 1
Chapter 1.2 System Software 4
Chapter 1.3 Programming Tools and Techniques. 9
Chapter 1.4 Data: Its Representation, Structure and Management 15
Chapter 1.5 Hardware 23
Chapter 1.6 Data Transmission and Networking 26
Chapter 1.7 Systems Development Life Cycle 30
Chapter 1.8 Choosing Applications Software 34
Chapter 1.9 Handling of data in Information Systems 36
Chapter 1.10 Designing the User Interface 37
Chapter 1.11 Characteristics of Information Systems 38
Chapter 1.12 Implications of Computer Use 39
Chapter 1.1 Hardware and Software Definitions
A computer system consists of hardware and software.
Hardware Definition
The hardware is the physical part of the system.
All computer systems require at least four types of hardware.
• An input device is a hardware attached to the processor/computer to supply data to the processor/computer.
• An output device is a hardware attached to the processor/computer to relay information from processor/computer.
• A storage device is a hardware which can store data outside the processor in a form which is suitable for input back into the processor. o A computer system need external device for the following reasons:
In order to store files when the power to the processor is switched off.
In order to store files which are too large to be stored in the processor itself, until they are needed.
To allow for the transfer of data from one machine to another.
Communications Hardware
The need for communication hardware arises when different computers are connected.
• Network Card
To allow computer to communicate externally.
• Modem
To allow the computers to use the telephone lines for communication. It inter-converts Digital data to Analogue signal.
Software Definition
The software is the various sets of instructions which tell the system how to do things.
Difference between hardware
Chapter 1.1 Hardware and Software Definitions 1
Chapter 1.2 System Software 4
Chapter 1.3 Programming Tools and Techniques. 9
Chapter 1.4 Data: Its Representation, Structure and Management 15
Chapter 1.5 Hardware 23
Chapter 1.6 Data Transmission and Networking 26
Chapter 1.7 Systems Development Life Cycle 30
Chapter 1.8 Choosing Applications Software 34
Chapter 1.9 Handling of data in Information Systems 36
Chapter 1.10 Designing the User Interface 37
Chapter 1.11 Characteristics of Information Systems 38
Chapter 1.12 Implications of Computer Use 39
Chapter 1.1 Hardware and Software Definitions
A computer system consists of hardware and software.
Hardware Definition
The hardware is the physical part of the system.
All computer systems require at least four types of hardware.
• An input device is a hardware attached to the processor/computer to supply data to the processor/computer.
• An output device is a hardware attached to the processor/computer to relay information from processor/computer.
• A storage device is a hardware which can store data outside the processor in a form which is suitable for input back into the processor. o A computer system need external device for the following reasons:
In order to store files when the power to the processor is switched off.
In order to store files which are too large to be stored in the processor itself, until they are needed.
To allow for the transfer of data from one machine to another.
Communications Hardware
The need for communication hardware arises when different computers are connected.
• Network Card
To allow computer to communicate externally.
• Modem
To allow the computers to use the telephone lines for communication. It inter-converts Digital data to Analogue signal.
Software Definition
The software is the various sets of instructions which tell the system how to do things.
Difference between hardware