Sunday, March 1, 2009

How Microprocessors Work

The computer you are using to read this page uses a microprocessor to do its work. The microprocessor is the heart of any normal computer, whether it is a desktop machine, a server or a laptop. The microprocessor you are using might be a Pentium, a K6, a PowerPC, a Sparc or any of the many other brands and types of microprocessors, but they all do approximately the same thing in approximately the same way.

A microprocessor -- also known as a CPU or central processing unit -- is a complete computation engine that is fabricated on a single chip. The first microprocessor was the Intel 4004, introduced in 1971. The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 bits at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components (transistors wired one at a time). The 4004 powered one of the first portable electronic calculators.

If you have ever wondered what the microprocessor in your computer is doing, or if you have ever wondered about the differences between types of microprocessors, then read on. In this article, you will learn how fairly simple digital logic techniques allow a computer to do its job, whether its playing a game or spell checking a document!

How Hackers Work

Thanks to the media, the word "hacker" has gotten a bad reputation. The word summons up thoughts of malicious computer users finding new ways to harass people, defraud corporations, steal information and maybe even destroy the economy or start a war by infiltrating military computer systems.

While there's no denying that there are hackers out there with bad intentions, they make up only a small percentage of the hacker community. ­

The term computer hacker first showed up in the mid-1960s. A hacker was a programmer -- someone who hacked out computer code. Hackers were visionaries who could see new ways to use computers, creating programs that no one else could conceive. They were the pioneers of the computer industry, building everything from small applications to operating systems.

In this sense, people like Bill Gates, Steve Jobs and Steve Wozniak were all hackers -- they saw the potential of what computers could do and created ways to achieve that potential.

A unifying trait among these hackers was a strong sense of curiosity, sometimes bordering on obsession. These hackers prided themselves on not only their ability to create new programs, but also to learn how other programs and systems worked.

When a program had a bug -- a section of bad code that prevented the program from working properly -- hackers would often create and distribute small sections of code called patches to fix the problem. Some managed to land a job that leveraged their skills, getting paid for what they'd happily do for free.

As computers evolved, computer engineers began to network individual machines together into a system. Soon, the term hacker had a new meaning -- a person using computers to explore a network to which he or she didn't belong. Usually hackers didn't have any malicious intent.

They just wanted to know how computer networks worked and saw any barrier between them and that knowledge as a challenge. ­

In fact, that's still the case today. While there are plenty of stories about malicious hackers sabotaging computer systems, infiltrating networks and spreading computer viruses, most hackers are just curious -- they want to know all the intricacies of the computer world.

Some use their knowledge to help corporations and governments construct better security measures. Others might use their skills for more unethical endeavors.

In this article, we'll explore common techniques hackers use to infiltrate systems. We'll examine hacker culture and the various kinds of hackers as well as learn about famous hackers, some of whom have run afoul of the law.

The Hacker Toolbox - The main resource hackers rely upon, apart from their own ingenuity, is computer Internet, only a relatively small number of hackers actually program code. Many hackers seek out and download code written by other people. There are thousands of different programs hackers use to explore computers and networks. These programs give hackers a lot of power over innocent users and organizations -- once a skilled hacker knows how a system works, he can design programs that exploit it. code. While there is a large community of hackers on the

Malicious hackers use programs to:

  • Log keystrokes: Some programs allow hackers to review every keystroke a computer user makes. Once installed on a victim's computer, the programs record each keystroke, giving the hacker everything he needs to infiltrate a system or even steal someone's identity.
  • Hack passwords: There are many ways to hack someone's password, from educated guesses to simple algorithms that generate combinations of letters, numbers and symbols. The trial and error method of hacking passwords is called a brute force attack, meaning the hacker tries to generate every possible combination to gain access. Another way to hack passwords is to use a dictionary attack, a program that inserts common words into password fields.
  • Infect a computer or system with a virus: Computer viruses are programs designed to duplicate themselves and cause problems ranging from crashing a computer to wiping out everything on a system's hard drive. A hacker might install a virus by infiltrating a system, but it's much more common for hackers to create simple viruses and send them out to potential victims via email, instant messages, Web sites with downloadable content or peer-to-peer networks.
  • Gain backdoor access: Similar to hacking passwords, some hackers create programs that search for unprotected pathways into network systems and computers. In the early days of the Internet, many computer systems had limited security, making it possible for a hacker to find a pathway into the system without a username or password. Another way a hacker might gain backdoor access is to infect a computer or system with a Trojan horse.
  • Create zombie computers: A zombie computer, or bot, is a computer that a hacker can use to send spam or commit Distributed Denial of Servicespam. (DDoS) attacks. After a victim executes seemingly innocent code, a connection opens between his computer and the hacker's system. The hacker can secretly control the victim's computer, using it to commit crimes or spread
  • Spy on e-mail: Hackers have created code that lets them intercept and read e-mail messages -- the Internet's equivalent to wiretapping. Today, most e-mail programs use encryption formulas so complex that even if a hacker intercepts the message, he won't be able to read it.

Cool Sites

www.Popsci.com
www.HowStuffWork.COm

A Plastic Bicycle

Innervision: Photo courtesy of BikeCommuters.com

Forget the carbon-fiber bike that costs more than your house. How about one made of plastic? The Innervision bike is a design concept by industrial designer Matt Clark that ditches high-cost complex materials for pre-molded plastic parts.

Clark's design eliminates the labor-intensive welding and heat treatment process associated with modern bike manufacturing. The current prototype has an inner and outer frame that is made of polypropylene -- that could be replaced with recycled plastic in the future. Prototype components were thermoformed and welded together without adhesives, but future versions could be compression-molded. While we're not expecting Lance to saddle up anytime soon, a lower-cost alternative for more social riders might be of interest.

Shades of the Future

Hindsight: Billy May

Looks like Lance Armstrong might have a new pair of sunglasses for his comeback tour. The blogs lit up in the past few weeks with attention surrounding a pair of Nike sunglasses that increase a rider's peripheral vision from the standard 180 degrees to up to 240.

Given Lance's pension for wearing yellow, the new specs could come in handy. Only problem is that Nike isn't actually making the glasses. Confused? We dug into the mystery.

If it looks like a Nike product and has marketing material that looks like a Nike product, then it must be ... a student with too much time on his hands and a working knowledge of Photoshop? It ends up that Nike has nothing to do with the seemingly impressive technology.

Our contact with Nike confirmed that the company is asking the rogue inventor, Billy May, to remove the swoosh branding from his design.

May is a self-proclaimed broke, unemployed recent college graduate from Washington and Lee University with little engineering background, who's looking for his big break. Hope this helps.

So if Nike isn't involved, does that mean the glasses won't work? Not so fast. May has created two prototypes that don't look as pretty as the mockup but provide a proof of concept. With a lens (possibly a Fresnel lens) with high-power negative focal length on the peripheral portion of the glasses, wearers can cram more into their peripheral vision.

The glasses are like "bifocals for their peripheral vision." The tradeoff is a slight distortion of that peripheral view. An annoyance to a guy on a Sunday stroll, but perhaps an acceptable side effect for those in sports and the military, where identifying motion is more important than any details.

Sound too good to be true? May thought the same, but a prior art search and some old-fashioned digging hasn't found anything to deter his quest.

All he needs now is some big-shot sports manufacturer with a hefty R&D budget to help develop the concept. Or maybe a consumer advocate to push for said financial backing. Lance, you busy?