Unit 1 Types Of Computers

COMPUTER TYPESCRITERIA OF CLASSIFICATION

HISTORY METHODS OF DEALING WITH DATA GENERATIONS MANUFACTURERS WIDELY ACCEPTED CLASSIFICATION

TYPES OF COMPUTERSIN HISTORY

• Pre-mechanical computers

• Mechanical computers

• Electronic computers

• Optical computers

• Biological computers

Pre-mechanical computers

• an example of a computer with no moving parts

• transforms information about stellar and planetary positions into information about important dates and events (harvests, etc.) Stonehenge

Mechanical computers

early designs for more traditional computers - based on mechanical techniques.

Slide rule

Abacus

Electronic computers

Optical computers

• current research in computer architecture includes much work on the design of computers which use light beams to perform computation; these machines should be smaller, faster and cooler than current electronic machines

Biological computers

• computers based on DNA: problems are encoded on strands of DNA which are mixed in solution and react to form DNA-coded answers

COMPUTER TYPESCRITERIA OF CLASSIFICATION

HISTORYTWO BASIC KINDSGENERATIONSMANUFACTURERSWIDELY ACCEPTED CLASSIFICATION

ANALOG COMPUTER

1. Analog computers measure the continuous change in something

– Current in a wire – Movement of the tide – Rate at which a wheel turns

2. More complicated to build than digital computers

3. Analog computers are very rare today

DIGITAL COMPUTERS

1. Use discrete numbers (whole digits) to control the electrical circuits

2. Built of switches that are either on or off – Can not have values in-between 0 or 1 like the

analog computer – 1 turns the switch on – 0 turns the switch off

3. Almost all computers built today are digital computers

COMPUTER TYPESCRITERIA OF CLASSIFICATION

HISTORYTWO BASIC KINDSGENERATIONSMANUFACTURERSWIDELY ACCEPTED CLASSIFICATION

First Generation - Vacuum Tubes

1. From 1946 to 1956 • did from 2,000 to 16,000 additions per

second • Had main memory 100 bytes to 2 kilobytes

2. Used vacuum tubes

3. Very large machines • special rooms to house them with air

conditioning • specially trained technicians to run &

maintain

Second Generation - Transistors

1. From 1959 to around 1965

2. Smaller, faster, and more reliable used transistors 6,000 to 3,000,000 operations/s main memory 6 kilobytes to 1.3 megabytes Contained in four cabinets about 6 feet high

by 4 feet wide, each weighing 250 pounds

3. one-tenth the price of a 1st Generation

4. become common in larger businesses and universities

Third Generation - Integrated Circuits

1. Form 1965 to around 1972 2. Used integrated circuits – many transistors

on one piece of silicon 3. Smaller, faster, more reliable, and lower in

price – Size of a stove or refrigerator, some can fit on

desktops – Can do 100,000 to 400,000,000 operations per

second – Cost about one-tenth the amount of second

generation computers

4. Computers become very common in medium to large businesses

Fourth Generation - Microprocessors

1. From 1972 until now 2. Used large scale to very large scale integrated circuits

– Put more than one IC on a silicon chip – Can do more than one function

3. smaller, faster, more reliable, and lower in price – Size of a television or much smaller – Can do 500,000 to 1,000,000,000 operations/second

– Cost one-tenth, or less, the amount of third generation 4. very common in homes and business

Future Computer Generations

1. Most likely the following will happen to computer technology

– It will become lower in price – Computers will become smaller and faster – Computers will have larger memories and

more storage space

2. Computers will become an integral part of everyone's life

HISTORYTWO BASIC KINDSGENERATIONSMANUFACTURERSWIDELY ACCEPTED CLASSIFICATION

COMPUTER TYPESCRITERIA OF CLASSIFICATION

COMPUTER TYPESCRITERIA OF CLASSIFICATION

HISTORYTWO BASIC KINDSGENERATIONMANUFACTURERWIDELY ACCEPTED CLASSIFICATION

WIDELY ACCEPTED WAYS

• SIZE (Early days): mainframe, minicomputer, microcomputer.

• SIZE (Now): Floortop, Desktop, Laptop, Palmtop, Wearable.

• POWER: Supercomputer, server, enterprise server (mainframe), mid-range server (minicomputer), PC.

PC

• computer designed for general use by a single person.

• PCs were first known as microcomputers because they were a complete computer but built on a smaller scale than the huge systems in use by most businesses.

DESKTOP

• A PC that is not designed for portability.

• you will set the computer up in a permanent location.

• Most desktops offer more power, storage and versatility for less cost than their portable brethren.

Laptop

• Also called notebooks.• Laptop are portable computers that

integrate the display, keyboard, a pointing device or trackball, processor, memory and hard drive all in a battery-operated package slightly larger than an average hardcover book.

Palmtop

• More commonly known as Personal Digital Assistants (PDAs)

• palmtops are tightly integrated computers that often use flash memory instead of a hard drive for storage.

• usually do not have keyboards but rely on touchscreen technology for user input.

• A slightly larger and heavier version of the palmtop is the handheld computer.

Workstation

• A desktop computer that has a more powerful processor, additional memory and enhanced capabilities for performing a special group of task, such as 3D Graphics or game development.

Server

• A computer that has been optimized to provide services to other computers over a network.

• Servers usually have powerful processors, lots of memory and large hard drives.

Mainframe

• In the early days of computing, mainframes were huge computers that could fill an entire room or even a whole floor!

• the term mainframe has fallen out of use in favor of enterprise server.

• the term still used, particularly in large companies to describe the huge machines processing millions of transactions every day.

Minicomputer

• term rarely used anymore, minicomputers fall in between microcomputers (PCs) and mainframes (enterprise servers).

• Minicomputers are normally referred to as mid-range servers now.

Supercomputer

• Costs hundreds of thousands or even millions of dollars.

• Most are comprised of multiple high performance computers working in parallel as a single system.

• Used for military purposes or in large companies

Wearable

• The latest trend in computing

• Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, visors and even clothing!