Limited-function early computers
The Jacquard loom, on display at the Museum of Science and Industry in Manchester, England, was one of the first programmable devices.

The history of the modern computer begins with two separate technologies—automated calculation and programmability—but no single device can be identified as the earliest computer, partly because of the inconsistent application of that term. Examples of early mechanical calculating devices include the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism, an ancient astronomical computer built by the Greeks around 80 BC.[4] The Greek mathematician Hero of Alexandria (c. 10–70 AD) built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums that might be considered to be a means of deciding which parts of the mechanism performed which actions and when. This is the essence of programmability.

The "castle clock", an astronomical clock invented by Al-Jazari in 1206, is considered to be the earliest programmable analog computer.[verification needed] It displayed the zodiac, the solar and lunar orbits, a crescent moon-shaped pointer travelling across a gateway causing automatic doors to open every hour,and five robotic musicians who played music when struck by levers operated by a camshaft attached to a water wheel. The length of day and night could be re-programmed to compensate for the changing lengths of day and night throughout the year.

The Renaissance saw the invention of the mechanical calculator, a device that could perform all four arithmetic operations without relying on human intelligence, in 1642. The mechanical calculator was at the root of the development of computers in two separate ways ; initially, it is in trying to develop more powerful and more flexible calculators that the computer was first theorized (Charles Babbage, Alan Turing) and then developed (ABC, Z3, ENIAC...) leading to the development of mainframe computers, but also the microprocessor, which started the personal computer revolution, and which is now at the heart of all computers regardless of size or purpose, was invented serendipitously by Intel during the development of an electronic calculator, a direct descendant to the mechanical calculator.

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem.

Conventionally a computer consists of some form of memory for data storage, at least one element that carries out arithmetic and logic operations, and a sequencing and control element that can change the order of operations based on the information that is stored. Peripheral devices allow information to be entered from external source, and allow the results of operations to be sent out.

A computer's processing unit executes series of instructions that make it read, manipulate and then store data. Conditional instructions change the sequence of instructions as a function of the current state of the machine or its environment.

The first electronic computers were developed in the mid-20th century (1940–1945). Originally, they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs).[1]

Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space.[2] Simple computers are small enough to fit into mobile devices, and can be powered by a small battery. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". However, the embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.

Buy A Discount Computer And Get The Same Features As That Of A New Computer - But At Half The Price!

The person that wants a low cost computer may be a student or the ordinary business man. The answer to this question can be answered better by asking another question. Why should I buy a discount computer? The way computers change so much, you can buy a computer now and it will be outdated in six months or less. So not can students and businessmen benefit with buying this type of computer, but the person who wants a computer without paying a high price is the targeted market.

Cost effectiveness of low cost computers is much higher than that of a regular computer. Discount computers versus regular ones, has to be the easiest choice you will ever have to make. These computers can provide everything you need, for a price that is affordable to you. Because the price is right and you can have every thing you could possibly need. These computers are not costly. You could even afford two if necessary!

Discount Versus Regular Computers

Finding low cost computers is achievable by looking at flyers in the newspaper, at discount stores, and web sites online. You can also check with schools. There are many great computers for fair price. You can find discount computers with just the same amount of storage, memory, and software as new ones. The difference is the cost. Students, business people and or those who work from home can afford to have a desktop or laptop at an affordable price. Because all discount computers come with a standard software package, a cheaper computer is actually the best deal.

When you think about a these discount computers, you may think they are only 'used' and you don't want a 'used' computer. This not the case with a low cost computer; it is actually a low cost computer with many of the same features as an expensive one. You won't lose quality by buying a low cost computer. Even if you find sales with very cheap prices, it could be because of a slight blemish or other exterior flaw. This does not affect the inner workings of a computer.

Some Points to Remember

Low cost computers come with enough memory, the same standard software package, and storage space equivalent to high price computers. The look is the same, there may be a blemish or flaw in the exterior, but sometimes this is true of the higher priced ones also. The last thing to remember is even if there is no keyboard or mouse; they are under $30 for a set. You may not get speakers with your discount computer, but you can find these cheaply elsewhere.

Summary:

Discount computers versus regular ones, has to be the easiest choice you will ever have to make. These computers can provide everything you need, for a price that is affordable to you. Because the price is right and you can have every thing you could possibly need. These computers are not costly. You could even afford two if necessary!