Information Technology Introduction to Computers Professor Adnan Khalid

Introduction to Computers Definition Of Computers: Definition Of Computers: “The Word Computer is derived from the word “compute” which means to calculate. The computer, therefore, can be defined as a calculating device that can perform arithmetic and logical operations.” “The Word Computer is derived from the word “compute” which means to calculate. The computer, therefore, can be defined as a calculating device that can perform arithmetic and logical operations.” “Computer is defined as a device that accepts input, processes it and gives an output. “Computer is defined as a device that accepts input, processes it and gives an output.

Introduction to Computers Input Processing Output

Types of Computers Analog Computers Analog Computers Digital Computers Digital Computers Hybrid Computers Hybrid Computers

Analog Computers Analog computers are use to measure continuous values. Analog computers are use to measure continuous values. Examples of analog computers are thermometers and analog clocks. Examples of analog computers are thermometers and analog clocks.

Digital Computers Digital means discrete. With digital signals everything is described in two states either on or off, either 0 or 1. Digital means discrete. With digital signals everything is described in two states either on or off, either 0 or 1. Examples of digital computers are digital watches and personal computers. Examples of digital computers are digital watches and personal computers.

Classification of Digital Computers Super Computers Super Computers Mainframe Computers Mainframe Computers Mini Computers Mini Computers Micro Computers/PC Micro Computers/PC

Super Computers Super Computers are the largest, the fastest and the most expensive computers in the world. Super Computers are the largest, the fastest and the most expensive computers in the world. They handle huge amounts of data and can perform more than one trillion calculations per second. They handle huge amounts of data and can perform more than one trillion calculations per second. They are used in weather forecasting, and modeling complex processes like nuclear fission. They are used in weather forecasting, and modeling complex processes like nuclear fission.

Mainframe Computers They are based on the principle of strong physical computing power. They are based on the principle of strong physical computing power. They are sensitive to variations in temperature and environment. They are sensitive to variations in temperature and environment. They have a large storage capacity. They have a large storage capacity. They can use a wide range of software. They can use a wide range of software.

Mini Computers They were introduced in the 60’s. They were introduced in the 60’s. They have less capacity as compared to mainframes. They have less capacity as compared to mainframes. They provide facility of direct operation. They provide facility of direct operation. They were mainly used for data processing and in industry. They were mainly used for data processing and in industry.

Micro Computers They are commonly used nowadays. They are commonly used nowadays. They are cheap and easy to use. They are cheap and easy to use. They have limited input and output capacity. They have limited input and output capacity. They are self-contained units and are to be used by one person. They are self-contained units and are to be used by one person.

Types of Micro Computers Desktop Computers Desktop Computers Laptop Computers Laptop Computers Palmtop Computers Palmtop Computers

Desktop Computers Single user machines. Single user machines. They can fit on a desk. They can fit on a desk. They can be interconnected to form a network. They can be interconnected to form a network. Their speed depends upon the processor. Their speed depends upon the processor. They are cheaper and sold in millions. They are cheaper and sold in millions.

Laptop Computers They are small, mobile personal computers that can fit in your lap. They are small, mobile personal computers that can fit in your lap. They weigh from one to three Kg. They weigh from one to three Kg. They are also called Notebooks. They are also called Notebooks. They run on a battery or from an external AC/DC adapter that can charge the laptop or supply the computer by itself. They run on a battery or from an external AC/DC adapter that can charge the laptop or supply the computer by itself.

Palmtop Computers These are computing devices small enough to fit in your palm. These are computing devices small enough to fit in your palm. A Personal Digital Assistant is a popular type of a palmtop. A Personal Digital Assistant is a popular type of a palmtop. Palmtops are also known as handled PCs. Palmtops are also known as handled PCs. They are commonly used for taking notes, s and telephony. They are commonly used for taking notes, s and telephony.

Hybrid Computers They are combinations of analog and digital computers. They are combinations of analog and digital computers. They demonstrate qualities of both analog and digital computers. They demonstrate qualities of both analog and digital computers. An example is cement plants. An example is cement plants.