Computers types

I, Computer: Definition
A computer is a machine that can be programmed to manipulate symbols. Its principal characteristics are:

§ It responds to a specific set of instructions in a well-defined manner.
§ It can execute a prerecorded list of instructions (a program).
§ It can quickly store and retrieve large amounts of data.

Therefore computers can perform complex and repetitive procedures quickly, precisely and reliably. Modern computers are electronic and digital. The actual machinery (wires, transistors, and circuits) is called hardware; the instructions and data are called software. All general-purpose computers require the following hardware components:

§ Central processing unit (CPU): The heart of the computer, this is the component that actually executes instructions organized in programs ("software") which tell the computer what to do.
§ Memory (fast, expensive, short-term memory): Enables a computer to store, at least temporarily, data, programs, and intermediate results.
§ Mass storage device (slower, cheaper, long-term memory): Allows a computer to permanently retain large amounts of data and programs between jobs. Common mass storage devices include disk drives and tape drives.
§ Input device: Usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.
§ Output device: A display screen, printer, or other device that lets you see what the computer has accomplished.

In addition to these components, many others make it possible for the basic components to work together efficiently. For example, every computer requires a bus that transmits data from one part of the computer to another.

What is an Abacus?

What is an Abacus?
Article about the abacus, picture of abacus, the salamis table, counting boards, the chinese abacus, where to buy an abacus, and the history and origins of the abacus, and related links for further study. The abacus was one of the earliest counting devices in Asia and parts of Europe. It is still used today for arithmetic: adding, subtracting, multiplying and dividing.

History of Computers

History of Computers
The development of the modern day computer was the result of advances in technologies and man's need to quantify. Papyrus helped early man to record language and numbers. The abacus was one of the first counting machines. .
Some of the earlier mechanical counting machines lacked the technology to make the design work. For instance, some had parts made of wood prior to metal manipulation and manufacturing. Imagine the wear on wooden gears. This history of computers site includes the names of early pioneers of math and computing and links to related sites about the History of Computers, for further study. This site would be a good Web adjunct to accompany any book on the History of Computers or Introduction to Computers. The "H" Section includes a link to the History of the Web Beginning at CERN which includes Bibliography and Related Links. Hitmill.com strives to always include related links for a broader educational experience. The material was originally divided into Part 1 & Part 2

What is Computer?

What is Computer?
Computer is an electronic device , which gets input from input devices , processes that input & finally gives us meaning - full out put.
OR
A machine that accepts input, processes it according to specified rules, and produces output.