Computer History Timeline
Abacus- considered as the earliest device for calculation, the abacus is used by the Europeans, Chinese and Japanese for simple addition, subtraction, multiplication and division.
Napier's Bone(1617)- invented by John Napier, this tool is made up of multiplication tables inscribed in a wood or bone.
Slide Rule (1620)- invented by William Oughtred, this is a single two-foot long ruler plotted with a logarithmic scale.
Pascaline (1642)- invented by Blaise Pascal. Fist operational calculating machine that could add large numbers.
Step Reckoner (1670)- Gottrified von Libnitz, who improved the Pascaline into a device that could add, subtract,multiply divide, and get square roots.
Difference Engine (1822)- Charles Babbage, an inventor who built a machine that automatically calculated mathematical tables, such as logarithmic and trigonometric tables.
Analytical Engine (1830)- ibid., this machine was not only able to perform calculations but also to store data in the memory and perform logical comparison.
Hollerith's Tabulating Mchine (1890)- invented by Herman Hollerith, this machine was capable of representing, reading and assembling data.
Mark 1- invented by Dr. Howard Aiken, it is the forst operating machine that could perform long computation automatically.
Electronic Numerical Integrator and Computers (1946)- developed by John Mauchly and J Presper Eckert.
Universal Automatic Computer (1951)- it is the first commercially available computer that could perform 1905 operations per second.
Generations of Computers
Fourth-generation Computers]
third-generation-computers
Second-generation-computers
First-generation computers
Types of Computers
1) Supercomputer
2) Mainframe Computer
3) Mini Computer
4) Work Station
Personal Computer
5) Types of Personal Computers
Tower Model
Desktop Model
Portable Computers
6) Types of Portable Computers
Notebook Computers
Subnotebook computer
Laptop Computer
7)Hand held computers
Palm Top
Personal Digital Assistant
How to Take Care of Your PC
1.) Computer need a good working temperature to work properly.
2.) All the cables must be tied together to avoid accidents
3.) Refrain from eating in front of the computer.
4.) Use AVR to regulate the electricity. Turn off during lightning.
5.) Do not bump or drop the computer.
6.) Avoid clutter around your computer.
7.) Always scan for viruses.
User's Health Risk and Prevention
- PC's are said to be "user-friendly" but it doesn't mean using them does not have health risk .
Good Working Habits
* Tap on your keyboard and mouse buttons gently
* Avoid long, uninterrupted periods of typing
* Avoid staring at the monitor for long times
Proper Workstation Design
* Position is well-ventilated
* Use an comfortable and adjustable chair
* Tilt the monitor or adjust the light source
* Use extendable legs of the keyboard
* Place the mouse where you can easily reach it
* Use document holder to Minimize vertical head movements.
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