Introduction to

Computers and

Programming Looking Back

Computers Today

Living in todays society with computers.

Computers Then

Computers were fairly mysterious devices

that only a few people knew about.

Around mid 1970s, a computer with a computational power of one of todays PCs would have filled a 9 by 12 foot room

and costs $100, 000.

Computers Then

= $100, 000 $2, 000

Brief History of Computing

Date Event

2000 BC The abacus is first used for computations.

1642 AD Blaise Pascal created a mechanical adding

machine for tax computations. It is unreliable.

1670

Gottfried von Leibniz created a more reliable

adding machine that can add, subtract,

multiplies and divides numbers and calculate

square roots.

Brief History of Computing

Date Event

1842

Charles Babbage designed an analytical

engine to perform general calculations

automatically. Ada Augusta (aka Lady

Lovelace) is a programmer for this machine.

1946

J. Presper Eckert and John Mauchly design

and built the ENIAC computer. It uses 18, 000

vacuum tubes and costs $500, 000 to build.

1971

Nicklaus Wirth designed the Pascal

programming language as a language for

teaching structured programming concepts.

Brief History of Computing

Date Event

1972

Dennis Ritchie of AT&T Bell Laboratories

designed the C programming language as

the implementation language for the UNIX

operating systems.

1984

Apple introduced the Macintosh, the first

widely available computer with a user-friendly graphical interface using icons, windows and a mouse device.

1989

Microsoft Corporation introduced Windows, a

Macintosh-like user interface for IBM

computers.

Components of a Computer

Main Memory

Central Processing Unit (CPU)

Control Unit

Components of a Computer

Central Processing Unit (CPU) performs the actual processing or manipulation of

information stored in the memory.

Computer Memory stores information of all types: instructions, numbers, names, lists

and pictures.

Components of a Computer

Secondary Storage provides additional data storage capacity on most

computers

Input and Output Devices enables computer users to communicate with the

computer

Categories of Computers

The following are the categories of

computers

Microcomputer (personal computer)

Server

Minicomputer

Mainframe

Supercomputer

Categories of Computers

Personal computers: Desktop computers for use at home and by

individuals.

Servers: Make programs and make data available for people who are linked to a

computer network. They are not used

directly.

Categories of Computers

Minicomputers: Are multi-user systems. They are usually used in small

organizations by using remote terminals or

personal computers.

Mainframes: Large, multi-user systems used in large organizations. They can

handle large data processing jobs.

Categories of Computers

Supercomputers: Ultra fast computers that are designed to process huge

amounts of scientific data.

End

Lecture material/s from the resources

used by Prof. Ritchie Mae T. Gamot for

previous AMAT 150 batch.

Introduction to C programming materials

(books, etc.)

Abacus

back

Pascaline or Arithmetique

back

Step Reckoner

back

Analytical Engine

back

ENIAC

Electronic

Numerical

Integrator

And

Computer

back

Pascal Code

back

C Code

back

Macintosh

back

Windows

next

Windows

back