Web Design Blog

Your plastic pal who’s fun to be with…*

August 20th, 2009 |

Your plastic pal who’d fun to be with…

For my first techy post, I’d like to introduce you to someone who you are already well acquainted with. Your computer.

It’s frustrating when it doesn’t work, I’m sure you’ve threatened to throw it out the window more than once, It does things you don’t want it to, and won’t do things you do. But if you’re like many people today, you’d be totally lost without it. In the past, you got your morning post to read while eating breakfast, and now you check your email and your favourite sites. but what goes on inside that whirring box you have under the table that you either kick by accident when sitting down or use as a coffee cup holder/footrest? Maybe you have a laptop or netbook instead of a desktop pc, the technology is inherently the same with a few changes for weight and power consumption primarily

Inside that tower you have some standard components. A hard drive, an optical drive, a motherboard, a CPU, some way to cool the CPU, some memory, a power supply, some way of outputting to a display and a bunch of cables.

The heart of your machine is the CPU or Central Processing Unit, more commonly known as the Processor.

Depending on what machine type you have this will change, there are desktop versions, laptop versions, netbook versions and server versions of these. Having said that, some laptops will have desktop versions, and vice versa. The main differences between Laptop and Desktop CPUs are the power consumption. Desktop CPUs will generally run at full speed most of the time, but laptop CPUS will be slower to generate less heat and will throttle themselves when running on battery to make the battery last longer. The CPU is what makes decisions in your machine.

Your hard drive is where all your files and programs are kept. It’s called permanent storage. When you switch on your pc, the computer looks to the boot sector of your hard disk, and loads whatever it finds there. It takes whatever files it needs and loads them for the Operating system to get you up and running. When you save files, you’re saving them to the hard disk. The hard disk is some platters, often coated aluminium that spin around at a huge speed. Laptop hard drives used to spin at 4200 revolutions per minute (RPM) and desktops used to do 5,400 RPM, but now desktop drives are available that spin at 10,000 rpm and server drives spin at up to 15,000 rpm. the platters spin on a spindle and each side of each platter has a head on a movable arm. This head moves over the surface of the disk at incredible speed reading and writing to the platter. when I say reading and writing, what it is actually doing, it’s really magnetising or de-magnetising the relevant parts of the disk. a magnetised part equates to a “1″ and a demagnetised is a “0″ the computer reads this and it’s programming tells it how to understand this and to show you what it’s programmed to do. this tends to be the most vulnerable part of your computer due to the speeds the disk is spinning. hard drives are airtight and are made in a dust free environment. if a speck of dust gets into a hard drive it could get between the platter and the head and cause the head to impact on the platter. If this happens the hard drive surface is damaged and will result in file corruption or total loss of the whole drive. for this reason it’s a really bad idea to move a machine when it’s on, as even though hard drives have shock protection built in, it’s easy to drop it and bye bye data. People often refer to the hard drive as memory and get the 2 confused.

Your memory is non permanent storage. It’s also called RAM, Random Access Memory. How do I describe what the Ram in your machine does? It acts like a buffer. Your CPU does things very fast, much faster than your hard drive can read or write. When you load something like a program from your hard disk, it gets copied into the RAM, and the RAM then feeds the data to the CPU as required. All running programs are loaded into the RAM also as running from the Hard drive would be painfully slow. Every time you restart your computer the ram is wiped clean, hence the non-permanent aspect of it. If for example you’re writing a letter in a Word processing package, that is being done in RAM. when you click save, it takes a copy of what you have in ram and writes it to the hard drive for permanent storage.

Your power supply unit (PSU) takes your normal 240 or 100 volt electricity supply, and transforms it to the voltages that your pc uses. Many people get the largest PSU they can, but this is really unnecessary. PSU’s are rated in watts, each device in your computer will use a certain amount of watts. for example a hard disk will generally require between 15 and 30 watts, your CPU will need anywhere between 50 and 105 watts depending on what type it is. An average machine with a graphics card will use about 400 Watts so installing a 500 watt psu is all that’s needed. Having that machine with a 1000 watt PSU is just burning electricity.

Your motherboard is what holds all those components together. The CPU and RAM are mounted on this in their respective sockets, the hard drive is plugged into the correct port, and is powered from the PSU. The PSU is also plugged into the motherboard to supply it, the CPU and RAM their power. The motherboard has Bridges, it provides the link between the CPU and the ram, it also uses the Northbridge and South bridge to connect to external things like the PCI bus, the ethernet controller, the audio chip, the USB BUS and others. What are they I hear you scream…They’re for another day I’m afraid.

If you have any questions feel free to mail me on zygomorphic@webdesignwhim.com