TYPES AND GENERATIONS OF COMPUTERS

INDEX

OBJECTIVES

To Study the different types of computers, ie: Embedded Computers Special Purpose Computers General Purpose Computers

To Study Different Generations of Computers.

To list out advantages and disadvantages of each type of computer.

To look into brief history and describe key features of different types of computers.

GENERAL PURPOSE COMPUTERS

A general-purpose computer is one that, given the appropriate application and required time, should be able to perform most common computing tasks.

Personal computers, including desktops, notebooks, smartphones and tablets, are all examples of general-purpose computers. The term is used to differentiate general-purpose computers from other types, in particular the specialized embedded computers used in intelligent system.

ENIAC, designed and built in the 1940s, was the first general-purpose computer. ENIAC weighed 30 tons and covered an area of about 1,800 square feet. In contrast, a current smartphone weighs a few ounces and is small enough to slip into a pocket.

LAPTOPSA laptop is a portable computer that contains the computer, monitor, keyboard, and fingerpad all in one unit. When laptops first became available, they were bulky and very expensive. As demand for laptops has grown, they have become cheaper to manufacture and purchase.

Advantages of Laptops Laptops are compact and light to carry around.

Wireless networking allows people access to the Internet and emails whilst travelling.

The latest batteries last for a lot longer nowadays before requiring a recharge.

People who commute or travel to their workplace, can carry their laptop with them.

Disadvantages of Laptops Laptops can be more expensive than desktops with similar

specifications.

Some people find the fingerpad very fiddly to use.

They cannot be customized like desktops, although some options are available at the time of purchase, e.g. extra RAM

Documents on screen can be very small if doing detailed work, due to the limitation of the screen size.

Personal ComputersA personal computer (PC) is a general-purpose computer, whose size, capabilities and original sale price makes it useful for individuals, and which is intended to be operated directly by an end user with no intervening computer operator. This contrasted with the batch processing or time sharing models which allowed larger, more expensive minicomputers and mainframe systems to be used by many people, usually at the same time. Large data processing systems require a full-time staff to operate efficiently.

ADVANTAGES They are cheap. They can be upgraded, with new components. They can be customised to suit a particular need.

DISVADVANTAGESThe disadvantages of desktops are:

They are heavy, bulky and not easily portable They take up a lot of space They get out of date very quickly due to advances in technology.

TABLET COMPUTERS

A tablet is a one-piece mobile computing device with a touchscreen and an on-screen virtual keypad.The tablet computer and its associated operating system began with the development of pen computing.

Tablets are equipped with sensors, including cameras, microphone, accelerometer and touchscreen, with finger or stylus gestures replacing computer mouse and keyboard.

Tablets may include physical buttons, e.g., to control basic features such as speaker volume and power and ports for network communications and to charge the battery. An on-screen, pop-up virtual keyboard is usually used for typing. Tablets are typically larger than smart phones or personal digital assistants at 7 inches (18 cm) or larger, measured diagonally.

Advantages of tablet PC portability (can work from everywhere and small enough to put in handbags)

can be used as a GPS navigation device

offer the same functionality as a normal computer

gesture recognition

great and handy for note taking

a multi-touch tablet permits you to interact with all the subject matter material quickly

comfort and ease of use

an effective learning and teaching enhancement tool

you can continue and finish their work while in transit

serve as an organizer to professional with much less paper on hand.

Disadvantages of tablet PC traditional keyboards are much more comfortable.

the screen size is too small in comparison with a laptop.

do not come with optical drives for use with CDs or DVDs.

potential screen damages and repair costs (more chances of screen damage to tablet PCs than to laptops; tablet computers are prone to problems like cracks, dead pixels, blown back-light bulbs and bad sensors).

difficulties to work on the small screen as compared to larger screen size of the laptops.

Mini-Computer

Minicomputers are used by small businesses & firms. Minicomputers are also called as “Midrange Computers”.

These are small machines and can be accommodated on a disk with not as processing and data storage capabilities as super-computers & Mainframes.

These computers are not designed for a single user. Individual departments of a large company or organizations use Mini-computers for specific purposes. For example, a production department can use Mini-computers for monitoring certain production process.

Popular Minicomputers

K-202 Texas Instrument TI-990 SDS-92 IBM Midrange computers

SPECIAL PURPOSE COMPUTERS

As the name states, a Special-Purpose Computer are designed to be task specific and most of the times their job is to solve one particular problem. They are also known as dedicated computers, because they are dedicated to perfom a single task over and over again.

Such a computer system would be useful in playing graphic intensive Video Games, traffic lights control system, navigational system in an aircraft, weather forecasting, satellite launch / tracking, oil exploration, and in automotive industries, keeping time in a digital watch, or Robot helicopter.

While a special purpose computer may have many of the same features found in a general purpose computer, its applicability to a particular problem is a function of its design rather than to a stored program. The instructions that control it are built directly into the computer, which makes for a more efficient and effective operation.

They perform only one function and therefore cut down on the amount of memory needed and also the amount of information which can be input into them. As these computers have to perform only one task, therefore, they are fast in processing. A drawback of this specialization, however, is the computer’s lack of versatility. It cannot be used to perform other operations

SUPER COMPUTERSThe most powerful computers in terms of performance and data processing are the supercomputers.

These are specialized and task specific computers, used by large organizations. These computers are used for research and exploration purposes, like NASA uses supercomputers for launching space shuttles, controlling them and for space exploration purpose.

The supercomputers are very expensive and very large in size. It can be accommodated in large air-conditioned rooms; some super computers can span an entire building.

In 1964, Seymour cray designed the first supercomptuer "CDC 6600".

Uses of Super ComputersSpace ExplorationSupercomputers are used to study the origin of the universe, the dark-matters. For these studies scientist use IBM’s powerful supercomputer “Roadrunner” at National Laboratory Los Alamos.

Earthquake studiesSupercomputers are used to study the Earthquakes phenomenon. Besides that supercomputers are used for natural resources exploration, like natural gas, petroleum, coal, etc.

Weather ForecastingSupercomputers are used for weather forecasting, and to study the nature and extent of Hurricanes, Rainfalls, windstorms, etc.

Nuclear weapons testingSupercomputers are used to run weapon simulation that can test the Range, accuracy & impact of Nuclear weapons.

Mainframe Computer

Mainframe computers are used by large companies to do complex tasks, such as manage and control all aspects of a large production line, or process millions of financial transactions.

Mainframes can carry out many different tasks at the same time. They also complete these tasks very quickly and reliably.

A mainframe may work continuously for many years, without failing.

The vast majority of mainframes are made by IBM, and cost between £30,000 and £500,000. The electricity costs for a mainframe could be as high as £10,000 a year.

Originally mainframes were the size of a large room (this is where the name comes from), however modern mainframes are about the size of a large wardrobe.

Embedded Computer

An embedded computer is frequently a computer that is implemented for a particular purpose. In contrast, an average PC computer usually serves a number of purposes: checking email, surfing the internet, listening to music, word processing, etc... However, embedded systems usually only have a single task, or a very small number of related tasks that they are programmed to perform.

Every home has several examples of embedded computers. Any appliance that has a digital clock, for instance, has a small embedded micro-controller that performs no other task than to display the clock. Modern cars have embedded computers onboard that

control such things as ignition timing and anti-lock brakes using input from a number of different sensors.

In general, an Embedded System: It is a combination of hardware and software to performs a specific task.

Is a system built to perform its duty, completely or partially independent of human intervention.

Is specially designed to perform a few tasks in the most efficient way. Interacts with physical elements in our environment, viz. controlling and driving a

motor, sensing temperature, etc.

Most embedded systems are time critical applications meaning that the embedded system is working in an environment where timing is very important: the results of an operation are only relevant if they take place in a specific time frame.

Embedded systems are considered when the cost of implementing a product designed in software on a microprocessor and some small amount of hardware, is cheaper, more reliable, or better for some other reason than a discrete hardware design.

Embedded computers may be economical, but they are often prone to some very specific problems.

Another problem with embedded computers is that they are often installed in systems for which unreliability is not an option. For instance, the computer controlling the brakes in your car cannot be allowed to fail under any condition.

An embedded system will have very few resources when compared to full blown computing systems like a desktop computer, the memory capacity and processing power in an embedded system is limited. It is more challenging to develop an embedded system when compared to developing an application for a desktop system as we are developing a program for a very constricted environment.

SYSTEM EXAMPLES: WATCH

It is a time display SYSTEM

Parts: Hardware, Needles, Battery, Dial, Chassis and Strap

Rules:

All needles move clockwise.

Only a thin needle rotates every second.

A long needle rotates every minute.

A short needle rotates every hour.

All needles return to the original position after 12 hours.

SYSTEM EXAMPLES: WASHING MACHINE

It is an automatic clothes washing SYSTEM

Parts: Status display panel, Switches & Dials, Motor, Power supply & control unit, Inner water level sensor and solenoid valve.

Rules:

Wash by spinning

Rinse

Drying

Wash over by blinking

Each step display the process stage

In case interruption, execute only the remaining.

Five Generation Of Computers

First Generation Of Computers

Second Generation Of Computers

Third Generation Of Computers

Fourth Generation Of Computers

Fifth Generation Of Computers

First Generation Of Computers

The computers of this generation use electronic devices known as Vacum Tubes and punched cards to record data.

Period : 1940-1956

Size : Very Huge( Size of 3 rooms)

Devices Used : Vacum Tubes

Examples : Mark1, UNIVAC 1, EDVAC, EDSAC

Second Generation Of Computers

These computers use transistors in place of Vacum Tubes.

Period : 1957-1963

Size : Much Smaller Than First Generation Computers

Devices Used : Transistors

Third Generation Of Computers

Integerated Circuits are made by many transistors.

Period : 1964-1971

Size : Much smaller than second generation of computers

Devices Used : Integerated Circuits

Fourth Generation Of

Computers

A large number of integerated circuits were put together in a material called silicon chips. Silicon chips were reliable and cheap.

Period : After 1972 to present

Size : Very Small in Size

Devices Used : Silicon Chips

Fifth Generation Of Computers

These computers are based on artificial intelligence. Parallel processing and superconductors are used.

Period : Present and Beyond

Size : Very Small

Devices Used : Superconductors

Examples : Robots