Introduction to Computers

Introduction to ComputersBy: Paul Andrew V. Roa

What is a computer? A computer is an electronic device that

helps people perform different tasks. An electronic device which is capable of

receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals.

What is a computer? (Cont.) Computers are used in many different

ways to help us with all kind of tasks. Computing technology allows us to write letters, create pictures, make calculations, play games and send electronic mail.

History of Computers

Four Basic Period

A. Pre-Mechanical AgeB. Mechanical AgeC. Electro-mechanical

AgeD. Electronic Age

Pre-mechanical Age:3000 B.C. – 1450 B.C.1. Writings and Alphabets – communication

First humans communicated only through speaking and simple drawings known as petroglyths (signs or simple figurers carved in rocks). Many of these are pictographs or sketches that visually resemble that which are depicted.

Ideographs – symbols to represent idea or concepts.

Cuneiform – the first true written language and the first real information system. Devised by the Sumerians in 3100 B.C.

Pre-mechanical Age:3000 B.C. – 1450 B.C. (cont.) Around 2000 B.C., Phoenicians created

symbols that expressed, single syllable and consonants (the first true alphabet).

The Greeks late adopted the Phoenician alphabet and added vowels; the Romans gave the Latin names to create the alphabet we use today.

Pre-mechanical Age:3000 B.C. – 1450 B.C. (cont.)


2. Papers and Pens – input technologies Sumerians’ input technology was a stylus

that could scratch marks in wet clay. About 2600 B.C., the Egyptians wrote on

papyrus plant. Around 100 A.D., the Chinese made paper

from rags, on which modern-day paper-making is made.


3. Books and Libraries – output technologies Religious leaders in Mesopotamia kept

the earliest “books”. The Egyptians kept scrolls. Around 600 B.C., the Greeks began to

fold sheets of papyrus vertically into leaves and bind them together.

Pre-mechanical Age:3000 B.C. – 1450 B.C. (cont.)4. The First Numbering Systems.

Egyptian system

100 – 200 A.D. The Hindus in India created a nine-digit numbering system.

Around 875 A.D., the concept of zero was developed.


5. The First Calculator: The Abacus. The abacus was the man’s first recorded

adding machine. Invented in 500 B.C. by the Babylonians and popularized in Chine.

The Mechanical Age:1450-18401614

- John Napier introduces logarithms

1623 - Wilhelm Shickard, a professor at Germany invented the first mechanical calculator.

The Mechanical Age:1450-1840 (cont.)1625 - William Oughtred invented the slide

rule.

The Mechanical Age:1450-1840 (cont.)1642 - Blaise Pascal invented the pascaline a

mechanical calculation machine made out of clock gears and levers. It could solve basic mathematical problems like addition and subtraction.

The Mechanical Age:1450-1840 (cont.)1671

- Gottfreid Leibniz – invented a machine called the stepped reckoner that could multiply 5 digit to 12 digit numbers yielding up to 16 digit number.

The Mechanical Age:1450-1840 (cont.)1820 - Arithmometer is invented by Charles

Xavier Thomas De Colmar in France.

The Mechanical Age:1450-1840 (cont.)1821 - Charles Babbage invented the first,

modern computer design: a steam powered adding machine called “The Difference Engine”.


- Charles Babbage invented the “analytical engine”. It is a mechanical adding machine that took information from punched cards to solve and print complex mathematical operation.- thus Babbage is titled “father of computers”.


- The first program was written by Ada Augusta Lovelace, for Babbage’s Difference Engine. She is credited as the first computer programmer. Ada is named in her honor.

The Electromechanical Age:1840-19401. The Beginnings of Telecommunication

a. Voltaic Battery- The first electric battery, known as the voltaic pile, was invented in 1800 by Alessandro Volta.

b. Telegraph- Samuel F.B. Morse conceived of his version of an electromagnetic telegraph in 1832.

The Electromechanical Age:1840-1940

c. Telephone and RadioIn 1876, Alexander Graham Belle,

invented the first working telephone.

In 1852, George Boole develops binary algebra. This became knows as Boolean Algebra.


2. Electromechanical Computing1853

-Pehr and Edvard Scheutz complete the Tabulating Machine, capable of processinf 15 difit number, printing result and rounding off to 8 digit.1885

- Dorr Felt devises the Comptometer, a key drive adding and subtracting calculator. In 1889, he changed it into Comptograph with a built-in printer.


1890Herman Hollerith is the first person to used punched card.


Hollerith later went on to found the Tabulating Machine Company which late became the Computer Tabulating Recording Company. We know it today as IBM(International Business Machine).


1893The Millionaire, the first efficient four-function calculator, is invented by Otto Shweiger, a Swiss engineer.


1906Lee De Forest developed the Vacuum tube. This is important because it provided electrically controlled, switched; a necessity for digital computers.

The Electronic Age:1941-present.1941

Konrad Zuse built the first programmable computer called the Z3. A computer is programmable because it is able to follow instructions.

The Electronic Age:1941-present.1942

Howard Aiken built the Mark I the first stored-program computer. 8 feet tall, 51 feet long, 2 feet thick, weighed 5 tons, used about 750,000 parts, 500 miles of wires, 3-5 seconds per calculation.

The Electronic Age:1941-present.1942 The First Electronic Computer

John Atanasoff and Clifford Berry completed the first all-electronic computer, called the ABC(Atanasoff-Berry Computer).

Computer Generations

The 1st Generation of Computers (1951 - 1958) Vacuum tubes as their main logic

elements. Punch cards to input and externally

store data. Rotating magnetic drums for internal

storage of data and programs.

(cont.) First generation computers had vacuum

tubes, resistors, and welded metal joint. They were large, slow, expensive and

produce a lot of heat. Often broke down because of burned out

vacuum tubes.

(cont.) In 1945, Presper Eckert and John Mauchly

developed the first operational electronic digital computer, calle ENIAC, for the U.S. Army.

It was 1,000 times faster than Mark I, and could perform 5,000 additions per second.

Has more than 18,000 vacuum tubes and took up to 1,800 square feet of space.

(cont.) In 1951 the UNIVAC-1 became the first

commercially available computer. This computer was designed by Eckert and Mauchly and built by the Remington Rand Corporation.

In 1953 IBM 701 was invented, IBM’s 1st electronic business computer.

The 2nd Generation of Computers (1959 – 1953) Vacuum tubes are replaced by

transistors as main logic element. Magnetic tape and disk began to replace

punched cards as external storage devices.

Magnetic cores became the primary internal storage memory.