Technical Computer Peripherals Popular PC Cases

Computer Cases

Over the years I have seen quite a lot of very different cases. From the incredible and expensive when compared to a budget case to the nasty, take your finger off, if you are not careful cheap kind that have a flimsy chassis and very noisy fans. Whatever the cost, all new computer cases are supplied with all the screws required to fit the motherboard, drives, including CD-ROM, DVD, hard drive and floppy drive. The kit will also provide risers either plastic or metal to suspend the motherboard from the side panel or raise the board off the base and blanking plates for when you start to swap expansion cards. The case will include 5.25 inch and 3.5 inch covers for all the removable drive bays, an integral power supply and a mains lead.

Before I describe the difference and my personal experience between desktop, tower and bespoke (one-offs) cases I think it is first necessary to explain that cases are also manufactured in several form factors of which ATX is currently the most popular and replaces the previously popular AT form factor, offering many advantages over the others. For an explanation of the different form factors click here.

Desktop Case

The original desktop design was only described as full height, half height and slimline once manufacturers were able to adapt the expansion slots to a single riser card that worked through a single expansion slot. The riser card offers several expansion slots of its own on both sides, however the orientation of the cards also changed from vertically connected to horizontally connected. This allowed the expansion cards to be stacked one above the other using both sides of the riser instead of vertically inserted in a row. Simply offering these expansion slots on both sides of the riser, removed the need for the case to be full height. A simple shuffling of one hard drive bay to below the power supply or strategically mounted on its side made room for a CD ROM, Floppy drive, a couple of hard disks, the motherboard with all of the expansion cards connected through a single vertical riser and the monitor sitting on top of it all. This left room for the keyboard to sit in front of the case making it all into a presentable looking workstation. Of course the case was reinforced with a bar across the centre which aided support of the monitor and made for a sturdy but heavy design. Reducing the height from full size to half height and then slimline also produced a lighter case with less bulk metal.

Tower Case

Once you add your mouse, a mouse mat, a printer, a couple of speakers and a modem you run out of space on a modest desktop. If you then try to do any work, or find and use the phone which is somewhere on the floor, you may find the use for a tower case. Once mostly popular for housing servers with many internal hard drives, a tower case would normally stand on the floor next to the monitor and keyboard. If you were to put a tower case on its side it would possibly be as wide as most users desks.

A tower case offers better circulation of air in and out, simply by directing the flow from low at the front of the case through vents to high at the back through the power supply or vice versa. This has the effect of reducing the heat inside the case produced by components and devices and reduces the possibilities for hotspots, trapped air which is not being circulated in or out of the case.

The tower case became most popular when manufacturers offered reduced height units with less internal and removable drive bays. The mini tower and midi tower also included less powerful PSU's (Power Supply Unit) with fewer power connectors for internal devices, feet to offer some stability and reduction in noise vibration from the floor and there size allowed users to place them back on their desktops for easy access to removable disks and the on/off switch.

Bespoke Case

If you have looked inside a case made by companies such as Apricot, Packard Bell, Dell, Elonex or any other of the well known brand machines you will probably notice that the motherboard design is a one off, the layout is specific to that model and the highly integrated design of the system makes it bespoke. Upgrading is limited too, but not always only possible of the hard drive, memory and processor. Often the limited expansion slots are already populated with sound card, capture card or internal modem. If the motherboard should fail, there is no other choice but to contact the manufacturer. You are locked in to one company. Some of the designs are exquisite and very fashionable but as a result of the exotic implementations are absolutely useless when sold and used solely with the intent of lasting more than a few years. Obsolete Packard Bell's and Compaq's are two a penny if you look in the classifieds.

The more recent designs offered by many understanding manufacturers cater for expandability and offer upgradeability of important functions like graphics, memory, processor speed and storage. Some even integrate devices highly on the motherboard with options of disabling them should you wish. However, by there very nature you are often tied in to one manufacturer and are forced to send your beloved computer away for repair should the motherboard fail (with all its integrated complications and devices, each one increasing the chance of something going wrong) instead of popping down to your local dealer and buying a more up to date, compatible design from a manufacturer of your choice and fit it yourself or have them do it for you if they are reputable.

A quality case should also include a quality power supply unit (PSU). The difference between a cheap case and a more expensive one of the same type is primarily the PSU. The difference between a cheap case of the same type and power supply and a more expensive one is primarily the quality of finish that has been put into the manufacturer. The difference between identical cases from different manufacturers is greed (uhum !!) and colour ones are always more expensive than black or white.

Other Features

If your case is fairly old, it may have a turbo button on the front. This was connected to the motherboard inside and had the effect of slowing the computers clock to 8 MHz. Common with a 486 processor, but completely useless with a Pentium class. More likely, on a Pentium system, the old turbo button will be connected to the standby function on the motherboard and will instead put the computer in to a power saving mode when pressed. When a 486 was very popular and only a few had Pentiums, LED displays were used to indicate the speed of the processor inside. The LED was capable of displaying a range from 1 to 199 and would be configured manually during the build or updated manually should the processor speed change after an upgrade. To change the LED display to show a different value, it was simply a matter of rearranging jumpers on the back of the LED board. This exercise could be performed while the case was powered on without any concern if you are careful not to touch any metal object intentionally or by accident and power of the machine before refitting.

I mentioned earlier the difference in quality of PSU. Although not obvious to most users or a technician who doesn't actually look inside, a useful addition to any modern ATX form factor case is an external on/off switch at the back and part of the power supply. An ATX case incorporates a soft switch at the front which when operated may only have the effect of switching the computer to standby. To completely remove power from the system it is normally necessary to either flick the switch on the PSU to off, remove the plug or turn the computer off at the wall socket. An external on/off switch is often an indication that the PSU is of good quality. (Until the cheap clones start to offer that to).

New Life In The Old LED

It is possible if you feel capable, to turn the LED display upside down and also rearrange the jumpers on the back of the LED board to display a value in the range 1 to 901. The 1 at the end is always present (or it would simply be in the range 01 to 99), but displaying 451 (MHz) is better than 199 maximum.
This is a trick I found useful when upgrading many customers boards and processors from say a 486 DX4*120 to a Pentium 233 MMX when using the old case. Rather than disappoint them by simply disabling the LED I performed the reverse operation.

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