Monthly Archives: December 2009

Computer Basics – What’s Inside a Computer? Memory

Glossary, , , ,

Now that we have the base for the computer (motherboard) and the brain of the operation (CPU) covered, let’s see what else is inside a computer.

Memory. In the broad sense of the word, it includes all devices that deal with data storage. In its most used meaning, it refers to the primary storage, a fast but temporary type of data storage that the computer uses to store data from programs currently running in your computer and so forth. It can be accessed in any order regardless of its physical location within its circuits. Hence its name: Random Access Memory or RAM.

Secondary storage is also referred to as mass storage. In its most common form, it can be the computer’s hard disk drive, or its compact disk (CD) or digital video disk (DVD) drive. It can store bigger amounts of data than the primary storage, but the data access and transfer times are much slower.

Smart readers will have noticed that these two forms of data storage are complementary, i.e. one has speed but low capacity, and the other capacity but slow speed. This is why they both exist in a computer. All the programs, all the files, documents, pictures, videos, etc. are stored in the secondary data storage device. As needed, the CPU calls for certain data needed for the execution of a program and the data gets transferred into the primary data storage device, where it’s readily available for immediate use without slowing down the computer due to slow access times. Generally speaking, once the computer is done with the data in the primary storage device, it flushes it from it, and writes anything that needs to be kept for future use to the secondary data storage device.

The above oversimplified cycle is, in a nutshell, what the computer is doing when operating. The computer CPU operates on data – it gets the data from the mass storage device and stores it temporarily in the faster storage device – it uses the data to perform its calculations and execute programs – it writes to the mass storage device the results of its calculations and programs execution that need to be stored for future use.

There is only one other thing the computer does, and that is sending data to other devices. That will be the subject of the next few articles.

Computer Basics – What’s Inside a Computer? CPU

Glossary, Technical Tips

Having covered the basic for the computer internals, the motherboard, let’s see what’s attached to it. Let’s start with the CPU. CPU = Central Processing Unit. Also known simply as the processor, it is the part of the computer responsible for the actual execution of your programs, the brain of the operation if you will. Every time you press Enter to execute a command or start a program, every time you click on a link or an email to open them, and so forth, it is the CPU that executes those commands. Inside your computer, if you were to locate it, it’d look like a square-shaped, black, flat component attached to the motherboard; It will – surprisingly – be located in a somewhat central position within it. While that description may fit more than one component in your motherboard, generally speaking the CPU will be the largest one.

Since it is so common to read about a computer’s processing power and speed when looking at specifications, it is worthwhile to take a closer look at what it means and how it is measured. When talking about a computer’s processing power/speed, one is, generally speaking, talking about the CPU. I grazed in one my earlier articles the concept of computer speed. Let’s go a little deeper into it.

The basic concept is, the CPU’s power is measured by how many instructions it can carry out per time unit. The more instructions it can execute by, let’s say, 1 second, the more powerful it is. Related to this, although potentially deceiving, is the CPU’s clock speed rate. The what? the CPU’s clock speed rate. Simply put, it is the number of cycles per second (measured in Hertz, abbreviated Hz) in which the CPU operates. The more cycles per second, the less time an individual instruction should take to execute.

So, the next time you see anywhere, whether in a computer ad or in your screen when looking at your computer specifications, “CPU @ 2.4 GHz”, you will know they are talking about the CPU clock speed rate (2.4 GigaHertz, 1 giga = 1,000,000,000, so 2,400,000,000 cycles per second).

There you have it. The CPU.

Computer Basics – What’s Inside a Computer? Motherboard

Glossary, Technical Tips

This is the first in a series of articles about the parts inside a computer. And what better part to start with than the motherboard, also called main board or system board (logic board for Apple computers). In the context of computers, if you ever see the term mobo being used, that is what is referring to (motherboard).

So what is a motherboard anyways? If you’ve ever seen the inside of many electronic devices, computers included, you’ve probably seen a thin plastic-looking green (although it can also be blue and red) board with copper color lines running through it. That is a printed circuit board. Thanks to our friend Eisler, it has been used in radios, TVs, etc., since the 1950’s. In computers, a motherboard is the main printed circuit board, to which normally all the other components inside a computer are attached, one way or another, thus populating it. All the other components that will be covered in future articles on this series are parts attached to it.

So what does it do? It provides electric connectivity to the various other parts of a computer. Think of it as a city, with streets that take you from one destination to another (or watch the movie Tron and you will see a perfect animated illustration for it). Obviously it also provides other components mechanical support (holds all other parts together).

That’s pretty much it. Perhaps the most basic and fundamental part inside a computer, the motherboard.

The Newest Facebook Malware Threat

Computer Security

A new computer worm, Koobface.GQ has been detected as trying to spread through Facebook. What is a worm? it’s a type of malicious software that propagates by self-replication. In this case, the Koobface.GQ’s main aim is to spread itself via the social network Facebook and affect as many computers as possible. It displays a message on screen requiring users to enter some characters in order to avoid a computer restart. Only computers with Windows XP/2003 and earlier operating systems are potentially affected.

It publishes a link to a video in the affected user’s Facebook main site, which will be shared to all their contacts. If the link is followed, a website similar to YouTube’s (actually YuoTube) is displayed. If run, it will display a message asking for some characters to be entered in a field, to prevent the computer from shutting down within 3 minutes. After the 3 minutes have gone by, the computer will not be restarted, but if the characters are not typed, the message will not disappear and the computer will be blocked until users enter the characters.

What to do? make sure you have a good and up-to-date (important) virus scanner, and perform a full scan. If you need help with this or any other malware threat, feel free to contact me.

And make sure you keep good web surfing and emailing habits at all times.

But in any case, if infected, don’t neglect it. If you do, you might be opening a can of… well, them.

VoIP Communication

Technical Tips

First of all, what the blazes is VOIP? other than a funny sounding word, it’s an acronym that stands for Voice Over Internet Protocol, an alternate method of voice communication similar in function to traditional phones, but instead of using normal telephone lines, uses an internet connection to allow for audio communications.

There are several levels of operation with this type of audio communication. In the first and most basic one, you have two computers, both with a high speed internet connection, and a program that handles the communication between them. Skype is one of the main and most known programs to do that. Others exist as well such as ooVoo, and it’s even embedded in some IM (Instant Messaging) programs. One additional advantage of these programs, even at this level is that they also allow for videoconferencing, so you can have audio and video, and in some cases, even multiple videoconferencing with several people at the same time. This of course requires a higher speed connection than what it requires to just make plain audio calls.

The next level is where you are able to  actually also call a normal landline or cell phone from your computer. For a small fee, Skype allows you to do that. You cannot however receive phone calls on your computer, you can only make outgoing calls. This setup is good when you have a phone that you use to receive phone calls and you want to keep it free for incoming calls.

The last level is where you can also make outgoing calls from your computer, or sometimes just through a device hooked to your internet connection. Vonage is an example of a VOIP service that doesn’t depend on a computer to operate, just needs the small device and a phone. Others, like MagicJack, require a phone connected to your computer. If you use Skype at this level, you can use your computer without any other devices (if your computer has a microphone) or simply by plugging a headset to your computer.

Cost is a factor when deciding which of these to choose. As far as I know, MagicJack offers the best bang for the buck.  $39.95 plus shipping and handling includes the phone to connect to your computer and one year of free local and long distance calling to the United States, Canada, Puerto Rico and the US Virgin Islands. You can purchase an additional year of service for $19.95. While Skype might offer a similar cost plan, their “unlimited” calling is not really unlimited and there is a ceiling as to how many phone calls you can make in a day.

This emerging method of telecommunication is here to stay and will only get bigger. More and more people are considering as an alternative to traditional phone services and migrating to it.