* Four basic periods
Characterized by a principal technology used to solve the input, processing, output and communication problems of the time: 1. Premechanical,
3. Electromechanical, and
A. The Premechanical Age: 3000 B.C. - 1450 A.D.
1. Writing and Alphabets--communication.
1. First humans communicated only through speaking and picture drawings. 2. 3000 B.C., the Sumerians in Mesopotamia (what is today southern Iraq) devised cuniform 3. Around 2000 B.C., Phoenicians created symbols
4. The Greeks later adopted the Phoenician alphabet and added vowels; the Romans gave the letters Latin names to create the alphabet we use today. 2. Paper and Pens--input technologies.
5. Sumerians' input technology was a stylus that could scratch marks in wet clay. 6. About 2600 B.C., the Egyptians write on the papyrus plant 7. around 100 A.D., the Chinese made paper from rags, on which modern-day papermaking is based. 3. Books and Libraries: Permanent Storage Devices.
8. Religious leaders in Mesopotamia kept the earliest "books" 9. The Egyptians kept scrolls
10. Around 600 B.C., the Greeks began to fold sheets of papyrus vertically into leaves and bind them together. 4. The First Numbering Systems.
11. Egyptian system:
* The numbers 1-9 as vertical lines, the number 10 as a U or circle, the number 100 as a coiled rope, and the number 1,000 as a lotus blossom. 12. The first numbering systems similar to those in use today were invented between 100 and 200 A.D. by Hindus in India who created a nine-digit numbering system. 13. Around 875 A.D., the concept of zero was developed. 5. The First Calculators: The Abacus.
One of the very first information processors.
B. The Mechanical Age: 1450 - 1840
1. The First Information Explosion.
1. Johann Gutenberg (Mainz, Germany)
* Invented the movable metal-type printing process in 1450. 2. The development of book indexes and the widespread use of page numbers. 2. The first general purpose "computers"
1. Actually people who held the job title "computer: one who works with numbers." 1. Slide Rules, the Pascaline and Leibniz's Machine.
2. Slide Rule.
Early 1600s, William Oughtred, an English clergyman, invented the slide rule * Early example of an analog computer.
3. The Pascaline. Invented by Blaise Pascal (1623-62).
The Pascaline (front)
Diagram of interior
* One of the first mechanical computing machines, around 1642. 4. Leibniz's Machine.
Gottfried Wilhelm von Leibniz (1646-1716), German mathematician and philosopher.
The Reckoner (reconstruction)
2. Babbage's Engines
Charles Babbage (1792-1871), eccentric English mathematician
5. The Difference Engine.
* Working model created in 1822.
* The "method of differences".
6. The Analytical Engine.
Joseph Marie Jacquard's loom.
* Designed during the 1830s
* Parts remarkably similar to modern-day computers. * The "store"
* The "mill"
* Punch cards.
* Punch card idea picked up by Babbage from Joseph Marie Jacquard's (1752-1834) loom. * Introduced in 1801.
* Binary logic
* Fixed program that would operate in real time. 7. Augusta Ada Byron (1815-52).
8. The first programmer
C. The Electromechanical Age: 1840 - 1940.
The discovery of ways to harness electricity was the key advance made during this period. Knowledge and information could now be converted into electrical impulses. 1. The Beginnings of Telecommunication.
1. Voltaic Battery.
* Late 18th century.
* Early 1800s.
3. Morse Code.