Introduction to Computer by Teacher Joe

Introduction to

ComputersBy: Teacher Joe

What is Computer?

A computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.

Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU) and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.

HISTORY

Charles Babbage, He was an English polymath.He was a

mathematician, philosopher, inventor and mechanical engineer, who is best remembered now for originating the concept of a programmable computer.

Considered a "father of the computer",[2] Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs. His varied work in other fields has led him to be described as "pre-eminent" among the many polymaths of his century.

The first recorded use of the word “computer” was in 1613 in a book called “The yong mans gleanings” by English writer Richard Braithwait I haue read the truest computer of Times, and the best Arithmetician that euer breathed, and he reduceth thy dayes into a short number. It referred to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations.[

Etymology

The history of the modern computer begins with two separate technologies, automated calculation and programmability. However no single device can be identified as the earliest computer, partly because of the inconsistent application of that term

Mechanical aids to Computing

A few precursors are worth mentioning though, like some mechanical aids to computing, which were very successful and survived for centuries until the advent of the electronic calculator, like the Sumerian abacus, designed around 2500 BC of which a descendant won a speed competition against a contemporary desk calculating machine in Japan in 1946, the slide rules, invented in the 1620s, which were carried on five Apollo space missions, including to the moon[7] and arguably the astrolabe and the Antikythera mechanism, an ancient astronomical analog computer built by the Greeks around 80 BC.

Mechanical aids to Computing

Computer used every where

In schoolIn the OfficeIn the HospitalIn the LibraryFor DesignEverywhere

How does Computer Process Data?The way a computer functions is very

similar to the way you solve a problem using pen and paper. The first operation is we called the input.Input involves obtaining data.The second operation is we called the processing.Processing involves manipulation of the data. Manipulation means adding, subtracting, multiplying, comparing, etc. The third operation is we called output.Output involves sending the results of the processing, the information, to the users. The fourth operation, storage, involves keeping the data in an electronic store.

How does Computer Process Data?Input means putting data into the computer. To do this, we usually use a device called a keyboard, which look like a typewriter.Processing is done by a processor. The processor is like the brain of the computer. The processor does its job by executing program.A program is a set of a instructions for completing a job. The result of the processing are sent to output units. The commonly used output units are printer and monitors. The results produced by the processor are called output. Output is also known as information, which is the summarize data.

How does Computer Process Data?Data by itself, is not directly useful. However, information has meaning and is useful.The results of the processing are called the output.Output is also known as information.

The fourth operation, storage, describes a computer’s electronic storage capacity.

Look at the block diagram of a computer.The arrow show how data is moved from the input to the processor for processing and sent out as output or information. The processed data is saved into the storage and retrieved from it when needed.

Types of Computers

Computers range in size and capability. At one end of the scale are supercomputers, very large computers with thousands of linked microprocessors that perform extremely complex calculations. At the other end are tiny computers embedded in cars, TVs, stereo systems, calculators, and appliances. These computers are built to perform a limited number of tasks.

Desktop computers                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Desktop computers are designed for use at a desk or table. They are typically larger and more powerful than other types of personal computers. Desktop computers are made up of separate components. The main component, called the system unit, is usually a rectangular case that sits on or underneath a desk. Other components, such as the monitor, mouse, and keyboard, connect to the system unit.

Laptop computers                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Laptop computers are lightweight mobile PCs with a thin screen. They are often called notebook computers because of their small size. Laptops can operate on batteries, so you can take them anywhere. Unlike desktops, laptops combine the CPU, screen, and keyboard in a single case. The screen folds down onto the keyboard when not in use.

Laptop computers                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Laptop computers are lightweight mobile PCs with a thin screen. They are often called notebook computers because of their small size. Laptops can operate on batteries, so you can take them anywhere. Unlike desktops, laptops combine the CPU, screen, and keyboard in a single case. The screen folds down onto the keyboard when not in use.

Handheld computers                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Handheld computers, also called personal digital assistants (PDAs), are battery-powered computers small enough to carry almost anywhere. Although not as powerful as desktops or laptops, handhelds are useful for scheduling appointments, storing addresses and phone numbers, and playing games. Some have more advanced capabilities, such as making telephone calls or accessing the Internet. Instead of keyboards, handhelds have touch screens that you use with your finger or a stylus (a pen-shaped pointing tool).

Tablet PC                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Tablet PCs are mobile PCs that combine features of laptops and handhelds. Like laptops, they're powerful and have a built-in screen. Like handhelds, they allow you to write notes or draw pictures on the screen, usually with a tablet pen instead of a stylus. They can also convert your handwriting into typed text. Some Tablet PCs are “convertibles” with a screen that swivels and unfolds to reveal a keyboard underneath.