COMPUTER TYPES CRITERIA OF CLASSIFICATION ppt

Mechanical computers early designs for more traditional computers - based on mechanical techniques... Optical computers• current research in computer architecture includes much work on

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 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

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

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 1 st 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

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

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

• 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

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

• 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

• 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

• term rarely used anymore, minicomputers fall

in between microcomputers (PCs) and

mainframes (enterprise servers)

• Minicomputers are normally referred to as

mid-range servers now

• 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

• 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!