IBM 360 Series, Honeywell 6000 series.

IBM 1401, IBM 1620, UNIVAC 1108

ENIAC, EDVAC, UNIVAC 1

Input Unit	Output Unit
An input device feeds information to a computer system for processing.	output device reproduces or displays the results of that processing.
Input devices only allow for input of data to a computer.	output devices only receive the output of data from another device.
It is a peripheral device used to provide data and control signals to an information processing system such as computer.	It is a unit which sends data from the computer to another device.
Eg. keyboard, mouse	Eg. printer, monitor

Memory enables the computer to store the program. The memory unit is of two types:
(i) Primary memory
(ii) Secondary memory
The primary memory is used to store data temporarily and secondary memory stores the data permanently.

The control unit controls the flow of data between the CPU, memory I/O devices. It also controls the entire operations of a computer.

Punch cards also known as Hollerith cards are paper cards containing several punched or perforated holes that were punched by hand or machine to represent data.

(i) The transistor ("transfer resistance") is made up of semiconductors.
(ii) It is a component used to control the amount of current or voltage or used for amplification! modulation or switching of an electronic signal.

(i) Vacuum tubes contain electrodes for controlling electron flow and were used in early computers as a switch or an amplifier.
(ii) Vaccum tubes are big in size and consumed more power.

(a) Natural Language Processing
(b) Development of Robotics
(c) Parallel and Distributed computing
(d) Artificial Intelligence
(e) Development of Robotics

Optical Mouse	Laser Mouse
It is less sensitive towards the surface	Highly sensitive
Tracking power is less	Tracking power is more
Old technology	Latest technology
This uses the light source instead of ball to judge the motion of the pointer.	This uses Laser light
Optical mouse has 3 buttons	No. of buttons will vary from 3 to many

The three output devices are
(a) Plotter
(b) Speakers
(c) Multimedia Projector.
(i) Plotter:
Plotter is an Output device that is used to produce graphical Output on papers. It uses single colour or multi-colour pens to draw pictures.
(ii) Speakers:
Speakers produce voice output (audio). Using speaker along with speech synthesize software, the computer can provide voice output.
(iii) Multimedia Projector:
Multimedia projectors are used to produce computer output on a big screen. These are used to display presentations in meeting halls or in classrooms.

(i) Scanner:
Scanners are used to enter the information directly into the computer's memory. This device works like a Xerox machine. The scanner converts any type of printed or written information including photographs into a digital format, which can be manipulated by the computer.
(ii) Fingerprint Scanners: 
Fingerprint Scanner is a fingerprint recognition device used for computer security, equipped with the fingerprint recognition feature that uses biometric technology. Fingerprint Reader / Scanner is a very safe and convenient device for security instead of using passwords, which is vulnerable to fraud and is hard to remember.
(iii) Monitor:
Monitor is the most commonly used output device to display the information. It looks like a TV. Pictures on a monitor are formed with picture elements called PIXELS. Monitors may either be Monochrome which display text or images in Black and White or can be color, which display results in multiple colors. There are many types of monitors available such as CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) and LED (Light Emitting Diodes). The monitor works with the VGA (Video Graphics Array) card. The video graphics card helps the keyboard to communicate with the screen. It acts as an interface between the computer and display monitor. Usually the recent motherboards incorporate built-in video card.
(iv) Plotter:
Plotter is an output device that is used to produce graphical output on papers. It uses single colour or multi colour pens to draw pictures.

Computers size was drastically reduced. S.No	Generation	Period	Main Component used	Merits/ Demerits
1	First Generation	1942-1955		Big in size Consumed more power Malfunction due to overheating Machine Language was used Eg : ENIAC, EDVAC, UNIVAC
First Generation Computer - ENIAC, EDVAC, UNIVAC 1 ENIAC weighed about 27 tons, size 8 feet x 100 feet x 3 feet, and consumed around 150 watts of power
2	Second Generation	1955-1964		Smaller compared to First Generation Generated Less Heat Consumed less power compared to first-generation Punched cards were used. The first operating system was developed Batch Processing and Multiprogramming Operating System Machine language, as well as Assembly language, was used.
Second Generation Computers IBM 1404, IBM 1620, UNIVAC 1108
3	Third Generation	1964-1975		Computers were smaller, faster, and more reliable Consumed less power. High-Level Languages were used.
Third Generation Computers -IBM ·360 series, Honeywell 6000 series
4	Fourth Generation	1975-1980		Smaller and Faster Microcomputer series such as IBM and APPLE was developed Portable Computers were introduced.
5	Fifth Generation	1980-till date		Parallel, Processing Superconductors Computers size was drastically reduced. Can recognize Images and Graphics Introduction of Artificial Intelligence and Expert Systems Able to solve highly complex problems including decision making and logical reasoning.
6	Sixth Generation	In future		Parallel and Distributed computing Computers have become smarter faster and smaller Development of robotics Natural Language Processing Development of Voice Recognition Software.

(i) Basic components of computer :
The Basic components are I/O Unit, CPU, ALU, Control Unit, Storage Unit.
Input unit:
Input unit is used to feed any form of data to the computer. It can be stored in the memory unit for further processing.
Ex. Keyboard, Mouse, Scanner, Retinal scanner, Track ball.
Central processing unit:
CPU is the major component and it controls the operation of all other components such as memory, input and output units. The CPU has three components namely control unit, Arithmetic and logic unit (ALU) and memory unit.
Arithmetic and logic unit:
The ALU is a part of the CPU where arithmetic operations like addition, subtraction, multiplication, divisions and logical operations will takes place.
Control unit:
The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.
Output unit:
An output device is a hardware component that conveys information to the user in an understandable form.
Ex. Monitor, printer, plotter
Memory unit:
The memory stores everything that computer works with. The memory unit is of two types namely primary memory and secondary memory. The primary memory stores the data and instructions temporarily. Whereas the secondary memory stores the data permanently. The primary memory is volatile and secondary memory is non-volatile.