Transcript 2008-computer

Definition
 Computer
- An electronic device that has
the ability to store, retrieve, and process
data and can be programmed with
instructions that it remembers.
© Prentice-Hall, Inc
Gross Anatomy
 Hardware

Equipment associated with the computer
• Input devices, processor, output devices, storage
 Software

Instructions that tell the hardware what to do

Two categories of software:
• System software
• Application software
History of Computers
Modern computers result from
2 streams of evolution
 Mechanization of arithmetic

calculating machines
(hardware)
 Concept

of stored programs
process control (software)
© Prentice-Hall, Inc
A Brief History of the Computer
 First


“computer”?
The first actual calculating mechanism known
to us is the abacus, which was invented about
2000 years ago
Abacus: The art of calculating with beads
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer

Many references cite the French
mathematician, physicist, and
theologian Blaise Pascal as being
the inventor of the first mechanical
calculator in 1642, the Arithmetic
Machine
Adapted From: http://www.maxmon.com/history.htm
© Prentice-Hall, Inc
Liebniz calculator
A Brief History of the Computer

However, it now appears that the first mechanical
calculator may have been conceived by
someone else almost 150 years earlier than
Pascal's machine. Can you guess who?
Leonardo Da Vinci
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer

In the early 1800s, a French silk weaver called
Joseph-Marie Jacquard invented a way of
automatically controlling the warp and weft
threads on a silk loom by recording patterns of
holes in a string of cards
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer
 The
first device that might be considered
to be a computer in the modern sense of
the word was the Difference Engine to
automatically calculate mathematical
tables conceived in 1822 by the British
mathematician and inventor Charles
Babbage
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer
 The
Difference Engine was only partially
completed when Babbage conceived the
idea of another, more sophisticated
machine called the Analytical Engine
 The Analytical
Engine was intended to use
loops of Jacquard's punched cards to
control an automatic calculator, which
could make decisions based on the results
of previous computations
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer

Working with Babbage was Augusta Ada
Lovelace, the daughter of the English poet Lord
Byron. Ada, who was a splendid mathematician
and one of the few people who fully understood
Babbage's vision, created a program for the
Analytical Engine

Ada is now credited as being the first computer
programmer and, in 1979, a modern
programming language was named ADA in her
honour
Adapted
© Prentice-Hall,
From: http://www.maxmon.com/history.htm
Inc
A Brief History of the Computer

In 1939, a German engineer,
Konrad Zuse built the first
programmable, generalpurpose digital computer. His
computer was built from electric
relays to automate engineering
calculations

“I was too lazy to calculate and
so I invented the computer.”
© Prentice-Hall, Inc
A Brief History of the Computer

John Atanasoff invented the
Atanasoff-Berry Computer
(ABC) —the first electronic
digital computer. Built in
1939, this computer used
vacuum tubes and was
based on binary arithmetic.
It was never a fully
operational product.
© Prentice-Hall, Inc
A Brief History of the Computer

In 1944, Howard Aiken completed the Mark I, the
largest electromechanical calculator ever built. It
was built with electromechanical relays and
followed instructions punched in paper tape
© Prentice-Hall, Inc
A Brief History of the Computer

In 1945, Mauchly and Eckert
built the ENIAC (Electronic
Numerical Integrator and
Computer). The ENIAC was
built with 18,000 vacuum tubes
that failed on an average of
once every seven minutes

After the war, they created the
UNIVAC I - the first generalpurpose commercial computer
© Prentice-Hall, Inc
First-Generation Computers






1930s – 1940s
Vacuum tubes used as switches
Large computers
Extremely slow by today’s standards
Prone to frequent failure
Includes the ABC, Mark I, ENIAC, UNIVAC,
and others of similar design
© Prentice-Hall, Inc
Second-Generation
Computers
– mid-1960s
 Transistors used as switches
 Smaller than vacuum-tube-built
computers
 As much as a thousand times faster than
first-generation computers
 More reliable and less expensive
 1950s
© Prentice-Hall, Inc
Third-Generation Computers
 Late
1960s
 Hundreds of transistors packed into a
single integrated circuit on a silicon chip
 Dramatic reduction in size and cost
 Significant increases in reliability, speed,
and efficiency
 Mass production techniques to
manufacture chips inexpensively
© Prentice-Hall, Inc
Fourth-Generation Computers
 1970s
to present
 Complete
computer on a
chip
 Radical
change in the
appearance, capability
and availability of
computers
© Prentice-Hall, Inc