5.25-inch Drive Bay

5.25-inch external drive bays can hold several different types of hardware.

Optional Case Fan

Adding an optional case fan will extend the life of a computer.

Motherboard Battery

The motherboard battery is used to preserve the computer's time and BIOS settings while the computer is turned off.

3.5-inch Drive Bay

There are two types of 3.5-inch drive bays: internal and external.

5.25-inch Drive Bay

5.25-inch external drive bays can hold several different types of hardware. A DVD burner, like the one shown above, is just one example. DVD burners are similar to CD burners except they can store much more information. DVD stands for Digital Versatile, (or Video), Disk. DVD (+/-) R Double Layer discs burn at two depths on one side of a disc. They are capable of storing up to 8.5 Gabs of information. A Double Sided Dual Layered DVD disk burns at two depths on both sides of the disk. It is capable of storing up to 17 Gabs of information. CD-R/RW disks can only store up to 700 Mobs of information. DVD+R and DVD-R are two different formats for write-once DVD disks. DVD+RW and DVD-RW are two different formats for re-writable DVD disks. RW disks can be erased and re-recorded to, while R disks cannot. DVD-RAM disks are more like removable hard disks. They are not compatible with most DVD-ROM or DVD players. DVD-ROMs have a lower data transfer speed rating compared to CD-ROMs, but 1x for a DVD player is equal to around 9 xs for a CD player. 6x x 9x = 54x, which means a 6x DVD player's data transfer speed would be equivalent to a 54x CD-ROM.

5.25-inch Drive Bay

5.25-inch external drive bays can hold several different types of hardware. A CD-ROM drive, like the one shown above, is just one example. CD-ROMs hold around 700MBs, (or 700,000,000 bytes), of information. The data transfer speed rating associated with CD-ROM drives varies up to 56 xs. For each 1x that a CD-ROM is rated, it can transfer 150KBs of information in one second. For example: a 10x CD-ROM can transfer 1,500KBs of information per second. A 20x CD-ROM can transfer 3,000KBs of information per second. It is simply a standard used in order to be able to rate the speed of CD-ROM drives.

5.25-inch Drive Bay

5.25-inch external drive bays can hold several different types of hardware. A tape drive, like the one shown above, is just one example. Tape drives can store up to 200GBs of information on a single cartridge, making them an ideal choice for backing up a computer's hard drive. It takes longer to access information stored on tape drive cartridges as compared to CD or DVD disks, because the tape must be fast-forwarded or reversed to the location where the information is stored. For this reason, it is not a good idea to use tape drives for everyday use where you would want to access a file often.
5.25-inch drive bays are not limited to 5.25-inch drives only. You can install 3.5-inch drives using special adapter plates. You can install fan speed controls or even a digital display panel. There is also nothing wrong with just saving a bay for future expansion. The way technology changes so rapidly, who knows what may be available within only a few months.

5.25-inch Drive Bay

5.25-inch external drive bays can hold several different types of hardware. A CD burner, like the one shown above, is just one example. CD-R disks can store around 700MBs, (or 700,000,000 bytes), of information. The recording speed rating associated with CD-R drives varies up to 54 xs. It varies up to 32 xs for CD-RW drives. For each 1x that a CD burner is rated, it can record 150KBs of information in one second. For example: a 10x CD burner can record 1,500KBs of information per second. A 20x CD burner can record 3,000KBs of information per second. A CD-R drive can read and write information, but it cannot erase it. CD-R disks can be used in any CD-ROM player. A CD-RW drive can also read and write data, but it can also erase the data and rewrite new data, which is useful if you save something and later wish to remove it. CD-RW disks are not as compatible as CD-R disks, and are limited to CD drives capable of supporting the Multiyear standard. CD-RW drives can use both CD-R disks and CD-RW disks.

AGP Expansion Slot

the AGP expansion slot connects AGP video cards to a motherboard. The video card shown above is an AGP George FX 5500. Video expansion cards are also known as graphic expansion cards. AGP stands for Accelerated Graphics Port. AGP video cards are capable of a higher data transfer rate than PCI video cards. Video cards, like the one shown above, simply plug into an AGP slot and connect a monitor or other video display device to a computer. The "DVI Out" connector shown in picture above connects to a digital video display. DVI stands for Digital Video Interface. Video cards with a TV output connection are capable of displaying a computer's video on a television. Video cards with a TV input connection are able of displaying a television's video on a computer. The AGP card and the monitor are what determine the quality of a computer's video display. The photo below shows what an AGP slot looks like.

AGP slots and cards come in 4 different modes. You must be careful to match the card and slot with the correct mode. Some cards and slots are capable of running in more than one mode. AGP 1x mode is the oldest. It transfers data at 266MBs per second. AGP 2x mode transfers data at 533MBs per second. AGP 4x mode transfers data at 1.07GBs per second. The latest AGP mode is AGP 8x. It transfers data at 2.14GBs per second. Below is a picture of three PCI Express slots.

PCI Express is a more recent technology that is slowly replacing AGP. PCI Express x16 slots can transfer data at 4GBs per second, which is about double that of an AGP 8x slot. PCI Express slots come in Pie x1, Pie x2, Pie x4, Pie x8, and Pie x16. Pie x16 slots are used for video cards.

The photo above shows what a GPU looks like. GPU stands for Graphics Processing Unit. The video card is in charge of controlling the video display. Much like the CPU's relationship with the motherboard, the brain of the video card is the GPU. It is responsible for making the decisions for processing the video card's graphical input and output data. It is hidden under a fan and heat sink in the first picture to keep it cool so that it doesn't overheat.

Audio Cables

The audio cables shown above connect multimedia drives like a CD-ROM or DVD-ROM to a sound card. They allow the transfer of sound data to the sound card so that it can be decoded and played. The quality of a computer's sound depends primarily on the sound card and speakers. The 4 pin, (or wire), audio cable is for analog audio. The two pin, (or wire); audio cable is for digital audio. Analog audio is continuous. Digital audio is broken into pieces. The sound card takes digital audio and translates it into analog audio and vice-versa. The reason for this is that computers work with digital data and regular sound waves are analog signals. Analog audio is like the sunlight, with continuous light. Digital audio is like a strobe light, with rapid bursts of light. You could also think of analog like signing your name in cursive, with one smooth continuous line. Digital would be like typing your name, doing it one keystroke at a time. Audio cables are not normally required with later model computers.

Motherboard Battery

The motherboard battery is used to preserve the computer's time and BIOS settings while the computer is turned off. Some motherboards only need the battery in case of a power outage. They draw the needed electricity from the electrical outlet to power the clock. These motherboards save their BIOS information to EEPROM. EEPROM stands for Electrically Erasable Programmable Read Only Memory.

BIOS
Basic Input/Output System

BIOS stands for Basic Input/Output System. The photo above shows an example of what a built in BIOS program looks like. BIOS programs vary from computer to computer, but every computer has one. Without any disks or even a hard drive, the BIOS program is always available, written permanently on the BIOS chip. It is used to set up the computer's hardware. Every time you boot your computer, you have the option of entering "Setup." Setup is how you access the BIOS program. Only experienced users should alter the BIOS settings. Improper BIOS settings can cause major problems on a computer. The BIOS chip contains enough information to operate the computer all by itself. When the computer is first turned on (or booted), the BIOS program is in charge. After booting and performing a few system checks, the BIOS program turns the computer over to your operating system. Windows XP is an example of a common operating system. CMOS, which stands for Complementary Metal Oxide Semiconductor, is where the BIOS store its information. The CMOS area is usually located on the Chipset, or the Real Time Clock Chip (not the CPU clock). Some BIOS Chips also allow you to save your settings to EEPROM. EEPROM stands for Electrically Erasable Programmable Read Only Memory. Read Only Memory (or ROM), is normally just that, and can never be erased or changed. ROM memory retains its data even when the power is disconnected. EEPROM memory also retains its data when the power is disconnected, but it can be altered by electrically erasing it, so that new data can be entered. If the CMOS loses its BIOS information, the EEPROM can provide your BIOS with a backup copy of the computer's settings. Below is a picture of a BIOS chip. This chip is where the BIOS program is stored.

The Case

The computer case is a very important part of the computer. It protects all of the electronic components inside and provides adequate ventilation to prevent overheating. The case also should be capable of allowing you to expand your hardware if the need arises. Some cases only have 5 or 6 expansion bays. This may not be enough if you plan to add several drives. There also should be plenty of expansion slots on the back for adding AGP, ISA, PCI, Pie, or other expansion cards. There are currently two basic types of cases for two different types of motherboards. The ATX case is shown above. It is for the ATX type motherboard and is the one most commonly used today. There is also a microwatt case that is used with the slightly smaller microwatt motherboard. Before the ATX case, there was an AT case for the older AT type motherboards. Many cases are made so that ATX, microwatt, and even the older AT type motherboards will work in them. There are also several different sizes of cases. The larger cases have more expansion bays than the smaller cases have. The smallest case is the "desktop" type that lies flat. The next size up is the "mini tower," then the "mid tower," then the "full tower," and finally the "server," which is the largest. The server case is primarily used for server computers in businesses. The ATX mid tower case is the most widely sold case for personal use.

Case Fan

Case fans are relatively inexpensive and are extremely important. Computer components generate quite a bit of heat and must be kept as cool as possible. The case fan is the primary source of cooling for most computers. Although the importance of the fan is often overlooked, it is the key to a long life for a computer. Most computer cases are designed to allow a person to add one or more additional case fans.

Case Speaker

the picture you just clicked on is actually a built in motherboard speaker. The picture above shows what a case speaker looks like. The actual case speaker is hidden behind the front panel. Both are generally only used for computer warning beeps or an occasional rare generic sound from a program. Warning beeps are usually heard during startup if a keyboard is not connected, memory has gone bad or something like that. Otherwise, you seldom ever hear the case speaker. Some sound cards allow you to bypass the case speaker altogether and play the warning beeps or other sounds intended for the case speaker on your regular "good" speakers, but there is nothing wrong with using the case speaker to play these sounds.

Case Front Panel

The front panel of the mid tower case shown above has two external 3.5-inch drive expansion bays, and four 5.25-inch drive expansion bays. Most front panels have an on/off switch, as well as a reset switch that is used in cases where the computer locks up and won't respond. Most front panels also have a power on indicator light and at least one hard drive activity light. Case speakers are often located just behind the front panel. Some front panels also have USB, audio, and other easy to reach port connections.

Case Rear Panel

In the picture above you can see that there are a lot of openings on the back of a computer case. About halfway down on the left, is where the motherboard's input and output ports are located when installed. In the top left-hand corner you can see where the power cord plugs in from the wall outlet. Below that is the main power supply on/off switch. Barely visible, between the two, is a small switch that allows you to select different voltage types for different countries. Many parts of Europe, as well as other countries, use different electrical voltages than those used in the U.S. The larger circular shaped holes to the right cover the fan for the power supply. This fan not only cools the power supply, but it also helps cool the inside of the case as well. The small holes down the right side provide increased ventilation for the case. There is also a location for a second optional case fan behind the bottom half of these holes. Near the bottom, on the left-hand side of the case rear panel, are seven expansion slot covers. These covers can be removed to connect an AGP video card, Pie cards, PCI cards, or any other type of expansion cards that might need to be installed in one of these openings.