Computer Systems

We hear the word system all the time in everyday conversation - computer system, hi-fi system, storage system - but what does it mean? In ICT, we say that a system is a set of components, or parts, working together to do something useful.

So, a computer system is made up of several parts, all working together - but what are these parts? They fall into two main categories - hardware and software.

	Hardware Hardware is the physical components - the hard parts - that make up the computer system. If you can touch it, it's likely to be hardware! Hardware is used for inputting and storing information, and for outputting the results, e.g. on a monitor or to a printer. Click here to learn about computer components Click here to learn about inputs and outputs
	Software Software is the programs and data that make the hardware parts do the things you want them to. They are the non-physical parts - you cannot touch software. Examples of software include operating systems, such as Microsoft Windows or Linux, or applications such as Microsoft Office or Paint Shop Pro. Click here to learn about different types of software

The words hardware and software aren't only used with computers - you might also come across the terms used in hi-fi or DVD magazines, where DVD players, CD players, speakers, etc., might be referred to as hardware, and the films or music called software.

Platforms

The combination of hardware and software together is known as the platform. So, for example, a desktop PC running Microsoft Windows would be a typical platform.

For more information about different platforms, click here.

Firmware

Not all ICT systems are PCs sitting on someone's desk, and so not all software can be installed and run by inserting a CD-ROM or a floppy disc. Another word you might occasionally come across is firmware. This is where the software required to run a system is actually stored in the hardware itself - i.e. on a chip.

Firmware is usually used in embedded systems and hardware devices such as network routers, which are either too small or too inaccessible for the user to be able to insert any type of storage medium containing the software.

Desktop System

For your this course, you need to be able to distinguish between desktop computers and portable computers.

Desktop systems are designed to sit on your desk. They usually consist of separate base unit (the part that contains the processor, memory and hard disc), keyboard, mouse and display.

The base unit can be assembled from standard components, and are therefore easier, and cheaper, to upgrade - for example by adding more memory or a larger hard disc.

New technology - for example a new type of processor - usually appears first in desktop computers, where the amount of space and power consumption is less of an issue. This means that desktop computers are usually more powerful than portable computers.

Portable Systems

There are several types of portable computing device available, but the most common are:

Notebook Computers A notebook PC - also known as a laptop - is a general purpose computer. They contains all of the features generally found in a desktop PC, but combined into one unit with a fold-down screen. Power comes from internal batteries which can usually run the notebook for 3-4 hours. Most notebooks have a built in DVD or CD-ROM drive and a floppy disc, but sometimes these are external and are connect by a cable to save space inside the computer.
Personal Digital Assistants (PDAs) A personal digital assistant is effective an electronic diary and organiser. It allows the user to keep their address book and diary in one compact unit, but also has the added ICT benefits of being able to quickly search contacts, or copy and paste appointments. PDAs also have some features of standard computers, such the ability to create files and folders, and save information. Some of them can also connect to networks using Wi-Fi (wireless) technology. Many PDAs even allow users to install new programs. The one shown on the right runs a version of Microsoft Windows called Windows Mobile, and even comes with Pocket Excel, Pocket Word and Pocket Internet Explorer - which are compatible with the full desktop versions. PDAs sit in a cradle to charge their rechargeable batteries. The cradle also connects them to a desktop computer to synchronise files, contacts and addresses, so that information on both computers is always the same and up-to-date.
Tablet PCs A tablet PC is like a half-way house between a notebook or laptop computer, and a PDA. As you can see in the picture, it is about the size of a notebook computer, and it will have a similar computing power, but input and output is only through the screen using a stylus. Tablet PCs are suited to a certain type of application where there might be some graphical input, or ticking of boxes, but not much entry of text. They might be used in the quality control department of a factory, where the inspector would see a diagram of the product and can mark on any damage. They are also used in some Warwickshire schools to control interactive whiteboard in classrooms.

Problems with Portable Systems

So, you might be thinking to yourself, why doesn't everyone just have a portable computer so that they can carry it round with them all the time?

The components in laptop, or notebook, computers, have to be re-engineered to make them smaller so that they fit inside a portable case. Portable computers also run from battery power, so it's important that they consume as little power as possible so that the batteries last longer. These factors mean that portable technology usually arrives later, and is more expensive than, desktop technology.

In systems that are even smaller than laptop/notebook computers, such as palmtop computers and PDAs, input and output becomes more of a problem.

A PDA, for example, is far too small to be able to incorporate a full-size keyboard and a socket for a mouse (or a touchpad, like those found on notebook computers), so other methods have to be used. Most modern PDAs (and tablet PCs, of course) have a stylus (basically a pointed stick!) and a touch sensitive screen that allows you to either operate an on-screen keyboard, or write directly on the screen. The computer then attempts to use hand-writing recognition software to turn what you've written into text.

Finally, because of the limited physical space, portable computers usually have less data storage capacity. A laptop or notebook computer will typically have a smaller hard disc drive than a desk-top computer, so will not be suitable for all applications. Even smaller computing devices may not have a hard disc at all, and wil rely on solid-state storage - that is storage with no moving parts, such as the sort of memory cards you might find in a digital camera. Solid-state storage is usually more expensive, and can be slower, than a hard disc drive.

Your Task

1. Find an advert for a personal desktop computer. A good source of information would be an on-line retailer, such as PC World or Dell.

2. Copy and paste the advert into your word-processing application, e.g. Microsoft Word.

3. Describe what the specification actually means:
   
   

   • what processor does the computer have?
   • how much memory has it got?
   • what is the capacity of the hard disc?
   • how much larger is the hard disc than the main memory (don't forget to check the units)?
   • what accessories does it come with?
   • how do you think the performance of this computer would compare with that of the computer you are currently using?

4. Save the file and attach it to the assignment on the ECOS web-page. Remember that you must save and submit the assignment for me to receive your work.

If you have any problems completing this task, please send me a message using the E-Mail a Tutor link on the ECOS web-site.