Computers

ComputersBy: Buğra Şahin

2

What Are Computers And How Do They Work?

Bugra Sahin

A computer is a general purpose device that can be pro-grammed to carry out a finite set of arithmetic or logi-cal 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. Pe-ripheral devices allow information to be retrieved from an exter-nal source, and the result of operations saved and retrieved.The first electronic digital computers were developed between 1940 and 1945 in the United Kingdom and United States. Orig-inally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). In this era mechanical analog computers were used for military ap-plications.Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and oc-cupy a fraction of the space. Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by small batteries. 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.

3Bugra Sahin

History Of Computers

In 1801, Joseph Marie Jacquard made an improvement to the textile loom by introducing a series of punched paper cards as a template which allowed his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the de-

velopment of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability.

The Most Famous Image in the Early History of Computing

This portrait of Jacquard was woven in silk on a Jacquard loom and required 24,000 punched cards to create (1839). It was only produced to order. Charles Babbage owned one

of these portraits ; it inspired him in using perforated cards in his analytical engineThe Zuse Z3, 1941, considered the world’s first working programmable, fully automatic computing mac-hine.It was the fusion of automatic calculation with programmability that produced the first recognizable computers. In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer, his analytical engine. Limited finances and Babba-ge’s inability to resist tinkering with the design meant that the device was never completed—nevertheless his son, Henry Babbage, completed a simplified version of the analytical engine’s computing unit (the mill) in 1888. He gave a successful demonstration of its use in computing tables in 1906. This machine was given to the Science museum in South Kensington in 1910.In the late 1880s, Herman Hollerith invented the recording of data on a machine-readable me-

dium. Earlier uses of machine-readable media had been for control, not data. “After some ini-tial trials with paper tape, he settled on punched cards ...”[21] To process these punched car-

ds he invented the tabulator, and the keypunch machines. These three inventions were the foundation of the modern information processing industry. Large-scale automated data pro-cessing of punched cards was performed for the 1890 United States Census by Hollerith’s company, which later became the core of IBM. By the end of the 19th century a number of ideas and technologies, that would later prove useful in the realization of practical compu-ters, had begun to appear: Boolean algebra, the vacuum tube (thermionic valve), punched

cards and tape, and the teleprinter.During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a dire-ct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital

computers.Alan Turing is widely regarded as the father of modern computer science. In 1936 Turing provided an influential formalisation of the concept of the algorithm and computation with the Turing machine, providing a blueprint for the electronic digital computer. Of his role in the creation of the modern computer, Time magazine in naming Turing one of the 100 most influential people of the 20th century, states: “The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarna-tion of a Turing machine”.The ENIAC, which became operational in 1946, is considered to

be the first general-purpose electronic computer.EDSAC was one of the first computers to implement the stored-program (von Neumann) architecture.The Atanasoff–Berry Computer (ABC) was the world’s first electronic digital computer, albeit not programmable. Atanasoff is considered to be one of the fathers of the computer. Conceived in 1937 by Iowa State

College physics professor John Atanasoff, and built with the assistance of graduate student Clifford Berry, the machine was not programmable, being designed only to solve systems of linear equations. The computer did employ parallel computation. A 1973 court ruling in a pa-tent dispute found that the patent for the 1946 ENIAC computer derived from the Atana-soff–Berry Computer.The first program-controlled computer was invented by Konrad Zuse, who built the Z3, an electromechanical computing machine, in 1941. The first programmable

electronic computer was the Colossus, built in 1943 by Tommy Flowers.

4

Coding

Bugra Sahin

Computer programming (often shortened to programming, scrip-ting, or coding) is the time of designing, writing, testing, debu-gging, and maintaining the source code of computer programs. This source code is written in one or more programming langua-ges (such as Java, C++, C#, Python, etc.). The purpose of prog-ramming is to create a set of instructions that computers use to perform specific operations or to exhibit desired behaviors. The process of writing source code often requires expertise in many different subjects, including knowledge of the application doma-in, specialized algorithms and formal logic.

Within software engineering, programming (the implementation) is regarded as one phase in a software development process.

There is an ongoing debate on the extent to which the writing of programs is an art form, a craft, or an engineering discipline. In general, good programming is considered to be the measured application of all three, with the goal of producing an efficient and evolvable software solution (the criteria for “efficient” and “evolvable” vary considerably). The discipline differs from many other technical professions in that programmers, in general, do not need to be licensed or pass any standardized (or governmen-tally regulated) certification tests in order to call themselves “programmers” or even “software engineers.” Because the dis-cipline covers many areas, which may or may not include critical applications, it is debatable whether licensing is required for the profession as a whole. In most cases, the discipline is self-gover-ned by the entities which require the programming, and someti-mes very strict environments are defined (e.g. United States Air Force use of AdaCore and security clearance).

5Bugra Sahin

Construction Of A Computer

The first step in building a computer is deciding what type of ma-chine you want to build. Do you want a really inexpensive com-puter for the kids to use? A small, quiet machine to use as a me-dia computer in the living room? A high-end gaming computer? Or maybe you need a powerful machine with a lot of disk space for video editing. The possibilities are endless, and the type of machine you want to build will control many of the decisions you make down the line. Therefore, it’s important to know exactly what you want the machine to accomplish from the start.

Let’s imagine that you want to build a powerful video-editing computer. You want it to have a quad-core CPU, lots of RAM and at least 2 terabytes of disk space. You also want to have FireWire and USB 3.0 ports on the motherboard. Look for a motherboard that supports:

• Quad-core CPUs (either Intel or AMD)

• At least 8GB of high-speed RAM

• Four (or more) SATA hard drives

• FireWire connections (possibly in both the front and back of the case)

• USB 3.0 ports

Then it all needs to go in a case with enough space to hold mul-tiple hard disks and enough air -flow to keep everything cool.

With any computer you build, knowing the type of machine you want to create can really help with decision-making.

6Bugra Sahin

Best Computers Present

Maingear Alpha 24

The Maingear Alpha 24 came in third on our Top 100 list. The machine’s massive chassis ac-commodates a GeForce GTX 680 video card, a Core i7-3770K CPU, and up to 32GB of me-mory. You can play today’s triple-A game titles, and upgrade every major component to play tomorrow’s attractions, too.

Falcon Northwest Tiki

This diminutive, quiet, and extremely fast desktop PC landed at number 15 on our overall list. This is no budget box; rather, it’s a polished, purpose-built tiny gaming system. The heavily overclocked Ivy Bridge processor, a fast SSD, and a GeForce GTX 680 video card combine to make this the fastest system of its size.

Raspberry Raspberry Pi

This computer’s inventors see it as a means to an end: encouraging students to teach them-selves how to program before they enter college. But the incredibly low price on this tiny and surprisingly powerful computer helped it land in the number 18 position on our complete list. We dig the noble goal, but we also like tech toys, and this one is hard to beat.

Lenovo IdeaCentre A720

Coming in at number 30 on our Top 100 list, the A720 squeezes into a base the size of a small pizza box. That allowed Lenovo to flatten its 27-inch, 10-point multitouch display to less than one inch thick. Lay the display completely flat and you can use the computer as if it were an oversize, stationary tablet.

MicroExpress MicroFLEX 37B

Given the choice between beauty and a beast, we’ll almost always take the beast (at least when it comes to PCs). This affordable, high-performance PC is a strong general-purpose system and a decent gaming rig. Credit the fast Ivy Bridge CPU, Radeon HD 7850 GPU, SSD, Blu-ray drive, and 16GB of RAM for that. The MicroFlex 37B is number 32 on our complete Top 100 list.