The Computer Mechanic: Glossary

– stands for compact disk read / read-write. A CD ‘burner’. The term burner or burning comes from the fact that data or information is put onto a CD by a laser in the CD-R/RW unit which changes the chemical layer on the surface of a CD to either emit or block light. The speeds given for a CD-R/RW are usually stated, for example, 52 x 52 x 32. The fastest speed, usually given first, indicates how fast the unit can read information from a CD. The next fastest speed given (ie. In this example 52x) is the maximum speed at which a CD-R/RW can transfer information to a CD (how fast it can burn). The next fastest speed (in this case 32x) is how fast a re-writeable CD can have information transferred to it. Re-writeable CDs are similar to normal, write once CD-Rs but they can be written to many times, like a floppy diskette. Although not as stable as CD-Rs, CD-RW disks have the benefit of being used numerous times. A good idea for data backup, although if you plan on keeping data or photos for a long time, CD-R disks are better (and cheaper). Each ‘x’ means this: every second, a certain amount of data can be transferred from the CD to the computer. To make the story complete, this is 300KB every second. The numbers aren’t important though. The main point is that if a speed is, for example, 52x then all this means is 52 times the original transfer rate.

– The latest Mobile technology from Intel. This technology uses a type of CPU known as Pentium M or PM. It was designed for notebooks so that they will have a higher battery life – making them even more portable and so wireless (Wi-Fi) networking could be intergrated.

The Centrino CPU has a number of distinct features:

(1) Speed step technology – the CPU can alter its speed in reference to the task you are asking it to perform. Ie. If you are typing a letter, the computer is always going to be waiting for you to type – no matter how many words per minute you are, therefore the CPU, to conserve battery, will slow its processing speed to the bare minimum required. On the other hand, if you are editing video, the CPU will be running at its fastest possible speed.

(2) Produces less heat – due to using less power and the CPU having a lower 'clock rate'.

(3) 1024KB L2 cache – think of this like a desk. Most other CPUs have 512KB memory. This is not the system memory or RAM that you may be familiar with, but what is called cache which is very fast memory located inside the CPU. The reason why I asked you to think of a desk – the Centrino can fit 1024 sheets of paper on its desk, other CPUs can only for 512. It means that Centrino has to run to the filing cabinet (memory) less often than any other processor (has to leave its desk less often) making it far more efficient. That is why, although the speed of a Centrino may appear slower (ie. 1.5Ghz compared to a Pentium’s speed of 2.8Ghz), it is more efficient and its relative speed is 1.75 (ie. Multiply the Centrino speed by 1.75 to see how fast it compares to a Pentium 4).

- is the central processing unit. It's where all the work in the computer/laptop is performed. The CPU speed is usually given as two parts - the calculation speed (ie. 2.8Ghz) and the CPU's internal speed (ie. 533 FSB) which is how fast the information is sent to or from the CPU. The higher the speed, the quicker a task is performed (but, I might add here, that it is not just up to the CPU - hard drive and memory also play their part). For example, a 2.8Ghz CPU has 2,800,000 cycles every second (obviously very quick!). Therefore, the speed gained by upgrading the CPU to the next higher speed is not a lot for the average home user - you save a few microseconds. But, the higher the speed, the longer your computer will be able to handle what the future brings in terms of requirements to run software and perform tasks without you having to make another cup of coffee.

See also: Ghz and FSB.

– stands for Front Side Bus. Basically, the speed at which information flows around your computer to and from the CPU. Desktop machines are usually 533Mhz FSB (though 800Mhz is gaining popularity) while laptops are at the 400Mhz speed.

– stands for Giga Hertz. How many cycles per second the CPU is capable of doing. The higher the number, the faster.

– this is the place where information is stored on a more permanent basis in your computer. A Hard Drive (usually abbreviated HDD) is made up of a number of round, thin magnetic coated surfaces that spin. The faster these spin, the faster information is found. Desktop HDD are usually spinning at 7200rpm. Laptop HDD are usually 4200rpm but faster HDDs are out on the market.

HDD storage space is given in Giga Bytes (GB). To see how big a GB is, think of one GB as 1000 floppy diskettes (rough estimate – one floppy diskette hold 1.44MB data). So, to make it grander, a 40GB HDD is the rough equivalent of 40,000 floppy diskettes.

Hard drives also have another component – cache. This is similar to what we discussed when speaking about the Centrino. The HDD cache is a buffer of storage used when writing to the HDD or reading from it. A crude way I think of it is being able to remember a phone number. Desktop HDDs have an 8MB cache (usually) while laptop HDDs are still usually 2MB. So, using the phone number analogy, the 8MB HDD can record 8 digits before having to write them down while the 2MB HDD can only recall 2 digits. All this adds to a faster, more efficient HDD and computer.

- In the past, the classic virus which attached itself to other programs was the only major concern. In today's Internet environment, a new kind of menace which is especially made for attacks on the Internet are much more dangerous. Every computer on the web is vulnerable. Two categories of harmful code have become more important in the last two years: Worms and Trojan Horses. Such harmful tools are called Malware. The term was created by a combination of "malicious" and "software ".

– RAM stands for Random Access Memory – means it the memory can be accessed anywhere. What this means to you is that the computer’s memory (RAM) is the equivalent of a filing cabinet and you can pull things out of the cabinet and any section of any file. It is a place where the computer stores information on a temporary basis (unlike your hard drive which is permanent).

What does all this mean? Well, your computer uses memory to load the operating system when your computer is booting or loading up. Memory is used when you open an internet browser to search the internet, etc. A minimum these days is 256MB memory. Windows XP uses a lot of memory and uses it efficiently. The more you give it the better it runs. But memory is also used by the programs you want to use. If you edit photos, you need a lot of memory (512MB or 1024MB is desired). When buying a new computer, or if you want to upgrade an older computer or laptop, 512MB is desirable.

– what gives you the image on your monitor or screen. Most desktop computers will have a dedicated video card as opposed to a shared or integrated video device. The difference is is that dedicated video does not ‘steal’ memory from your computer. It has its own. Also, it is better at rendering graphics because it has its own graphics processing unit to do the work. Integrated video devices are allocated memory from the RAM or system memory and the computer’s CPU does all the work.

Most laptops have integrated video because the main focus of laptops is work like internet and word documents which do not require high graphic performance. But, as laptops are fast becoming replacements for desktop units many laptop manufacturers are making laptops with dedicated video for better game play and 3D capability.