case : Computer Hardware Buyers’ Glossary

Look for a recessed RESET switch so you won’t hit it by accident with your knee.

Most computers nowadays come in mini tower cases that can fit on the floor or desktop. Cases usually come in boring shades of beige. For $75.00 CAD (or less for multiples) you can have your computer, monitor and keyboard painted with a special plastic coating in any colour you want. A company called SPL Coatings has branches all over the world to do it. The new Pentium IV motherboards require a slightly deeper case than usual. If you buy a new case, you probably should get that extra room just in case. Make sure your case and motherboard are compatible. Most cases and motherboards are ATX (Advanced Technology Extended) form factor. Motherboards are shrinking all the time, and cases are shrinking with them. There are also mini-ATX and micro-ATX cases.

The Spec for the ATX case is really a standard for motherboards. It does not specify what I/O connections must be available on the back panel, but here is what they typically look like:

A more modern motherboard might present connectors like this:

• cyan: mouse
• purple: keyboard
• top: S/PDIF (Sony/Philips Digital Interconnect Format) audio optical out
• bottom: S/PDIF audio coax out
• IEEE (Institute of Electrical & Electronics Engineers) 1394a firewire port
• Switch for clearing CMOS (Complementary Metal Oxide on Silicon)
• four USB-2
• gigabit LAN (Local Area Network), two USB-2 ports
• gigabit LAN, two USB-2 ports
• orange: center/subwoofers,
• grey: rear speakers
• white: side speakers
• blue: Line in
• green: line out front speakers
• pink: mic in

Other possible connectors include HDMI (High-Definition Multimedia Interface) video, VGA (Video Graphics Adapter) video, USB-3, external SATA (Serial ATA), serial, parallel.

Modern motherboards consume more power and consequently give off more heat than computers of former years. Intel in response designed the BTX form factor, but it has not yet caught on.

Power supplies often come bundled with the case. Spend a little extra to get good quality and a slightly higher rating than necessary. A flaky power supply will cause no end of odd glitches.

Cases are usually sold without any fans. You will need to get at least one.

Cases, disks, motherboards etc. usually come without a full complement of screws and connectors. Before the sale, make sure these are all included.

Installing the Case

You need tiny fingers for this job. Borrow a child.

The connections are almost never documented. You have to take the case apart to see where wires go, use a continuity meter, and just plain experiment. Happily getting it wrong will rarely cause permanent damage, just frustration. With LED (Light-Emitting Diode) s, if the light does not work try attaching it the other way around. Happily, switches are not polarity sensitive.

Ask your case dealer to fill in a sheet like this on all the case connections. This sample chart is for a case 17" tower case I bought from DTI computers.

Installing the Motherboard

The back plate where the keyboard and other connectors poke through has mysterious little projections. These are to hold the plate in place by spring pressure against the back of the motherboard. They are not intended to be bent and wrapped around anything.

Installing the Hard Disk

Disks need good air circulation. Try to arrange empty bays top and bottom, and a good air flow unimpeded by cables. You might even consider a fan dedicated to cooling your disk drives.

Motherboard Sizes

You must make sure your motherboard upgrade fits your case. Originally cases were all large enough to handle any size motherboard. Now the match is much tighter.

I refer to the depth as the distance from the front of the motherboard to the back where the slots and connectors are. I refer to the width as the distance between the two sides of the motherboard. Others may refer to these as the length and width or width and length. To figure out which terminolgy a given vendor is using, the bigger number is the width and the smaller the depth.