Advertisement

  PPC > Computing Guides > What is it?  

 What are all the parts of my computer?

Ian Waugh guides you through the main points you need to know to talk the talk.

The case
Motherboard
Processor
Graphics card
Ports
Memory
Hard drive

Case. 

Case? What's in a case? Well, the gubbins of the computer is in the case, but there's more to the case itself than may meet the eye. First of all, there are three types of case - desktop, mini tower and full tower. 

The computer inside them may often be the same but the different types of case offer different advantages to the user.

The most common type of case is the desktop model. This is flat, rectangular and squat and useful 'cause you can stand a monitor on top of it. Providing it's not bigger than a 17". The drawback is - there's not a lot of room inside the case and it's quite cramped. If the layout hasn't been well designed you may have to remove various bits such as the power supply, disk drive or sound card if you want to add more RAM, another hard disk, a modem and so on.

The mini tower gives you a bit more room to breath. The motherboard is mounted vertically along one side of the case and you can access plug-in cards, RAM slots and so one much easier.

But not as easy as in a full tower which is a really just a bigger version of a mini tower. But you can get both hands inside it and installing and removing bits is much, much easier. If you enjoy upgrading, adding and removing parts then this is for you.

With PCs, all decent suppliers will offer you a choice of case. Often a full tower (and sometimes a mini tower) has a small premium over a desktop case. 

Remember - the more you like to fiddle, the bigger the case you should get.

Motherboard. 

The name says it all - the Mother and the Heart of the PC. This is the large printed circuit board you'll see in the case which houses the main components of the computer. These include the BIOS, the cache and the central processor. It has slots for plugging-in memory and, if it's a modern motherboard, probably I/O controllers and connections for serial, parallel and USB ports, floppy and hard disks. It also houses ISA and PCI slots for plugging in cards such as a video card, a modem, a sound card and so on.

Motherboards are incredibly complex and it's reassuring to know that most of us don't need to know exactly what they contain or how they work. Any complete computer system you buy ought to be optimally set up so the motherboard and all its bits are working together in perfect harmony.

However, if you intend to customise, change or add anything to the motherboard, read the manual carefully. Oh yes, with every computer you should get a manual for the motherboard. Keep it safe. Final words of wisdom - don't mess with the mother unless you're know what you're doin'!

Processor

The processor or CPU (Central Processing Unit) controls the computer. This is The Man (or Person if you insist on being politically correct). This is the brains. This does the business. CPUs have names, too, such as the 386, 486 and Pentium, Pentium II, III and 4. It executes instructions and transports data around the computer system.

Many computers are known by the name of the CPU chip inside it and the speed it runs at so you'll hear of a 486/66, a Pentium 300, P4 1400 and so on. As ever with computers, the faster the better.

Graphics card

Graphics cards are also known as video cards or video adapters and they're responsible for putting the image generated by the computer onto a monitor. The display can be in a number of resolutions such as 800 x 600, 1024 x 768 or 1280 x 1024 up to some seriously big numbers and use a range of colours from 16 or 256 right up to 16-bit, 24-bit or 32-bit which support millions of colours. The greater the resolution and the more colours the card displays, the more memory it requires and the longer it will take to draw the image.

For programs which require high-resolution graphics which change quickly such as games, you need a fast video card. The latest generation of games which use 3D graphics require special 3D cards to get the most out of them. Less frantic applications such as a wordprocessor or a spreadsheet don't need super fast graphics and are quite happy with a "standard" card.

Applications which rely more heavily on the display such as graphics applications and perhaps music applications whose displays need to be updated quickly in real-time will also benefit from a faster graphics card. 

Ports

These are the plugs and sockets on the back on your computer, more technically known as I/O or Input/Output Ports. They appear to the computer as a memory address and it simply sends data to this address or receives data from it. The most common ports are serial and parallel ports which are generally used to link to a printer. A serial port handles data one bit at a time. A parallel port, often known as a Centronics port, can handle several bits of data at once. And then there’s USB and FireWire, which are a different kettle of fish altogether.

Memory

The stuff DRAMS are made of. Sorry! Memory is where the computer does its sums, essentially an area where data can be stored, retrieved and manipulated. Many people call memory RAM which stands for Random Access 

Memory. It's not a particularly helpful acronym. It simply means that the computer can dive in and access any part of the memory, unlike a tape backup system, for example, where the computer may have to wade through meters of tape to reach a certain item of data.

RAM is volatile which means that when you remove the power, its contents is lost which is why you are taught from an early age to save often.

To confuse matters more, there is several types of RAM - DRAM (Dynamic RAM), SRAM (Static RAM), SDRAM (Static Dynamic RAM), EDO RAM (Extended Data Out RAM)... They all perform the same function but some do it more efficiently that others and different computer systems work better with different types of RAM.

Then there's ROM or Read Only Memory. This is a better acronym and it means that the computer can retrieve data from it but it can't write to it - rather like a locked floppy disk. There are lots of ROM chips in a computer, used to store set-up data and information which doesn't need changing. Data in ROM is remembered after switching off.

But then there's Flash memory which does let you change its contents and which also remembers it after switching off. This is popular in modems, for example. It lets you upgrade the operating system, say from 33.6kbps to 56kbps.

Hard drive

A technical description would probably go something like this - a collection of hard platters coated with magnetic material to which data can be written and read using a series of read/write heads. Modern drives typically have from two to eight platters which rotate at speeds from 3200 to 7200 rpm. The whole unit is sealed inside a case which prevents dust getting inside. The heads fly above the platters at a distance of from 10 to 25 millionths of an inch and a speck of dust could cause serious damage.

Hard drives have been getting cheaper and their storage capacity larger over the past few years. Rare now is the PC which comes with a drive smaller than 3Gb as standard. 5Gb and 8Gb drives are now very affordable. There are two main types of drive - EIDE and SCSI. This determines how the drive communicates with the computer. SCSI drives have always been faster but the latest generation of IDE/UDMA drives come pretty close although they work most efficiently under a truly multi-tasking operating system. 

However, the latest SCSI drivers can transfer data at up to 80Mb/sec. Speed is nice but it would only be of major benefit in disk-intensive applications such as working with large graphics files, and direct-to-disk digital audio and video recording.