Transcript Book Title - St. Francis Xavier University

CSCI-235
Micro-Computer in Science
Introduction
Course Overview
 Class

webpage
http://cs.stfx.ca/~ltyang/csci-235/
What Is a Computer?
A
machine that can be programmed to
accept data, process it into useful
information, and store it away

Data
• raw facts representing people and events

Information
• data that is organized, meaningful, and useful
© Prentice-Hall, Inc
The Processing Cycle of a
Computer
© 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 From: http://www.maxmon.com/history.htm
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
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 From: http://www.maxmon.com/history.htm
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 From: http://www.maxmon.com/history.htm
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 From: http://www.maxmon.com/history.htm
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 From: http://www.maxmon.com/history.htm
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
honor
Adapted From: http://www.maxmon.com/history.htm
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

The first computer “bug”
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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

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
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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
Computer System Components
 Hardware

Equipment associated with the system
 Software

Instructions that tell the hardware what to do
 People


Computer programmer: writes software
User: purchases and uses software
• Often called end-user
© Prentice-Hall, Inc
Hardware: The Basic Components
of a Computer

Four primary
components:




Input Devices
Processor
Output devices
Storage
© Prentice-Hall, Inc
Input Devices: Keyboard

Most common input device

Generates electrical signals
which are translated into
characters
© Prentice-Hall, Inc
Input Devices: Mouse

Moves over a flat surface

Movement of mouse ball causes corresponding
movement of pointer on screen
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The Processor
 Also
called central processing unit (CPU)
 Center of activity in the computer

Consists of electronic circuits
• Interprets and executes program instructions
• Communicates with input, output, and storage
devices
 Actually
© Prentice-Hall, Inc
transforms data into information
Storage: Primary Storage
 Used


to temporarily hold data
After it is retrieved from input device and
before it is processed
After it is processed and before it is released
to output device
 Temporary

(volatile) storage
Data in memory lost if power is lost or
program closed
© Prentice-Hall, Inc
Storage: Secondary Storage
 Provides

Separate from memory
 Common



long-term storage
media
Magnetic disks
Optical disks
Magnetic tape
© Prentice-Hall, Inc
Magnetic Disks

The most common storage media


Diskette: 3.5” flexible diskette in plastic case
Hard Disk: more storage capacity and faster
access than diskette
© Prentice-Hall, Inc
Optical Disks

Use a laser beam to read large volumes of
data inexpensively


CD-ROMs
DVD-ROMs
© Prentice-Hall, Inc
Magnetic Tape
 Stores
large amounts of data
inexpensively
 Often used for system backup
© Prentice-Hall, Inc
Software
 All
the programs that give the computer its
instructions
 Two
categories of software:
System software
© Prentice-Hall, Inc
Application software