CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

4.3. Checking Outside the Box

Now that you have looked at what is inside the box, you will want to see what gets added to the system — outside the box.

4.3.1. Casing and form factors

Part of the outside of the box is the box itself. There are many different form factors for the box, some of which dictate the form factor of the motherboard going into the case. Cases come most often in tower or desktop form factors, but are also found in forms that make them attractive for entertainment units and in extremely small forms for specific uses.

4.3.2. Input and output devices

Computers use many different kinds of input and output devices (also called I/O devices), which connect to the computer via one of the computer's ports. In the following sections, I give you an overview of the most common input and output devices.

4.3.2.1. Monitor

The different types of buses that can provide video services include

• ISA (Industry Standard Architecture), which runs at 8 MHz.

• PCI (Peripheral Component Interconnect), which runs at 33 MHz and 66 MHz.

• PCIe (Peripheral Component Interconnect Express), or PCI Express, is a high-speed serial bus, so its speed is measured differently than the others, which are parallel buses. PCIe has between 1 and 16 channels (1x–16x).

• PCI-X (Peripheral Component Interconnect Extended), which runs at 133 MHz.

• AGP (Accelerated Graphics Port), which runs at 66 MHz (but can be increased to 8x the base speed, or 528 MHz).

You have probably already guessed that the faster the ...