Input Devices:
Keyboard:
Keyboard (wired 1 wireless, virtual) is the most common input device used today. The individual keys for letters, numbers and special characters are collectively known as character keys. This keyboard-layout is derived from the keyboard of original typewriter.
Mouse:
Mouse (wired/wireless) is a pointing device used to control the movement of the cursor on the display screen.
Types of Mouses:
(i) Mechanical Mouse
(ii) Optical Mouse
(iii) Laser Mouse
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.
Track Ball:
Track ball is similar to the upside- down design of the mouse. The user moves the ball directly, while the device itself remains stationary. The user spins the ball in various directions to navigate the screen movements.
Retinal Scanner:
This performs a retinal scan which is a biometric technique that uses unique patterns on a person's retinal blood vessels.
Light Pen:
A light pen is a pointing device shaped like a pen and is connected to a monitor. The tip of the light pen contains a light-sensitive element which detects the light from the screen enabling the computer to identify the location of the pen on the screen. Light pens have the advantage of 'drawing' directly onto the screen, but this becomes hard to use, and is also not accurate.
Optical Character Reader:
It is a device which detects characters printed or written on a paper with OCR, a user can scan a page from a book. The Computer will recognize the characters in the page as letters and punctuation marks and stores. The Scanned document can be edited using a word processor.
Bar Code / QR Code Reader:
A Bar code is a pattern printed in lines of different thickness. The Bar code reader scans the information on the .bar codes transmits to the Computer for further processing. The system gives fast and error free entry of information into the computer.
QR (Quick response) Code:
The QR code is the two dimensional bar code which can be read by a camera and processed to interpret the image
Voice Input Systems:
Microphone serves as a voice Input device. It captures the voice data and send it to the Computer. Using the microphone along with speech recognition software can offer a completely new approach to input information into the Computer.
Digital Camera:
It captures images / videos directly in the digital form. It uses a CCD (Charge Coupled Device) electronic chip. When light falls on the chip through the lens, it converts light rays into digital format.
Touch Screen:
A touch screen is a display device that allows the user to interact with a computer by using the finger. It can be quite useful as an alternative to a mouse or keyboard for navigating a Graphical User Interface (GUI). Touch screens are used on a wide variety of devices such as computers, laptops, monitors, smart phones, tablets, cash registers and information kiosks. Some touch screens use a grid of infrared beams to sense the presence of a finger instead of utilizing touch-sensitive input.
Keyer:
A Keyer is a device for signalling by hand, by way of pressing one or more switches. Modern keyers have a large number of switches but not as many as a full size keyboard. Typically, this number is between 4 and 50.

(i) The Sixth Generation, computers could be defined as the era of intelligent computers, based on Artificial Neural Networks. This generation gave a start to parallel computing.
(ii) One of the most dramatic changes in the sixth generation will be the explosive growth of wide is a component of artificial intelligence
(iii) Robotics is a branch of engineering that involves the conception, design, manufacture, and operation of robots.
(iv) This field overlaps with electronics, computer science, artificial intelligence, mechatronics, nanotechnology and bioengineering.
(v) Artificial neural networks (ANNs) are computing systems inspired by the biological neural networks that constitute animal brains.
(vi) Such systems learn (progressively improve performance on) tasks by considering examples, generally without task-specific programming.
(vii) An ANN is based on a collection of connected units or nodes called Artificial Neurons (analogous to biological neurons in an animal brain).
(viii) Each connection (synapse) between neurons can transmit a signal from one to another. The receiving neuron can process the signal(s) and then signal neurons connected to it.
(ix) Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously.
(x) Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism.
(xi) Parallelism has been employed for many years, mainly in high-performance computing, but interest in it has grown lately due to the physical constraints preventing frequency scaling.
(xii) As power consumption by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.

Booting of computer:
(i) An Operating system (OS) is a basic software that makes the computer to work. When a computer is switched on, there is no information in its RAM.
(ii) At the same time, in ROM, the pre-written program called POST (Power on Self Test) will be executed first. This program checks if the devices like RAM, keyboard, etc., are connected properly and ready to operate. If these devices are ready, then the BIOS (Basic Input Output System) gets executed. This process is called Booting.
(iii) Thereafter, a program called "Bootstrap Loader" transfers OS from hard disk into main memory. Now the OS gets loaded (Windows/Linux, etc.,) and will get executed. Booting process is of two types.
1) Cold Booting
2) Warm Booting
(iv) Cold Booting:
When the system starts from the initial state i.e. it is switched on, we call it cold booting or Hard Booting. When the user presses the power button, the instructions are read from the ROM to initiate the booting process.
(v) Warm Booting:
When the system restarts or when Reset button is pressed, we call it Warm Booting or Soft Booting. The system does not start from the initial state and so all diagnostic tests need not be carried out in this case. There are chances of data loss and system damage as the data might not have been stored properly.

Non-Impact Printers:
(i) These printers do not use striking mechanism for printing. They use electrostatic or laser technology.
(ii) Quality and speed of these printers are better than Impact printers. For example, Laser printers and Inkjet printers are non-impact printers.
Laser Printers:
(i) Laser printers mostly work with similar technology used by photocopiers.
(ii) It makes a laser beam scan back and forth across a drum inside the printer, building up a pattern. It can produce very good quality of graphic images.
(iii) One of the chief characteristics of laser printer is their resolution - how many Dots per inch(DPI). The available resolution range around 1200 DPI. Approximately it can print 100 pages per minute(PPM).

Inkjet Printers:
(i) Inkjet Printers use colour cartridges which combined Magenta, Yellow and Cyan inks to create color tones.
(ii) A black cartridge is also used for monochrome output. Inkjet printers work by spraying ionised ink at a sheet of paper.
(iii) The speed of Inkjet printers generally ranges from 1-20 PPM (Page Per Minute).
(iv) They use the technology offering ink by heating it so that it explodes towards the paper in bubbles or by using piezoelectricity in which tiny electric currents controlled by electronic circuits are used inside the printer to spread ink in jet speed.
(v) An Inkjet printer can spread millions of dots of ink at the paper every single second.