Computer Maintenance – Glossary

GLOSSARY

Welcome to the glossary. This has been created to help you with some terms you might not be familiar with.

ACRONYMS

There are a lot of different acronyms used when talking about computers. Here are a few of the more common ones:

KB (Kilobytes) Used to define size – it means times one thousand.

MB (Megabytes) Used to define size – it means times one million.

GB (Gigabytes) used to define size – it means times one billion.

MHz (Megahertz) One million cycles per second – used to measure the speed of a CPU chip, memory modules, video cards, etc. Different chips run at different speeds and this should be the first thing looked at when deciding on a component.

GHz (Gigahertz) One billion cycles per second – used to measure the speed of a CPU chip. Different chips run at different speeds and this should be the first thing looked at when deciding on a component.

BIOS (BASIC INPUT OUTPUT SYSTEM)

The BIOS is another very important part of your computer that makes its home on the motherboard. "BIOS" stands for Basic Input/Output System, and usually resides on a series of chips on your motherboard. When you turn on your computer, the BIOS determines what hardware is installed. It finds out if the hardware is working and if any of the parts have their own BIOS. If it finds any BIOS type programming on any of the parts, it lets those parts take inventory before returning to its task. For example, most video cards have their own BIOS chip. So, the main BIOS turns control over to the video card until it is done, then resumes to check the rest of the computer.

All of this happens behind the scenes every time you boot. You may notice the POST, or Power On Self Test. When your BIOS tests the hard drive, floppy drive, and keyboard, you’ll see lights flash on them. Once all of this is done, your BIOS loads the operating system. It does this by looking for and reading your various boot-up files, such as Config.sys and Autoexec.bat. From there, your operating system takes over. As you can see, BIOS is important; every computer needs it and like CPU’s, it comes in different versions. BIOS versions are based on years. You can usually see what date your BIOS is by looking at the sticker on the chip itself, but if you don’t have a sticker, you can go to the BIOS screen on your monitor.

From time to time manufactures provide BIOS upgrades from their websites. These upgrades are “Flashed” or burned into your BIOS chip, overwriting the older version. Before performing a Flash upgrade of your BIOS, read the manufactures instructions carefully – if you make a mistake, your computer may not reboot!

CPU (CENTRAL PROCCESSING UNIT)

The main chip in your computer. Even faster than the genius in your math class, the Central Processing Unit can do millions of calculations per second! Your programs use all this calculating power to help you do useful things like write letters and balance your checkbook.

Cycles The speed at which a computer runs, usually given in millions of cycles per second (Megahertz). Every system has a clock that drives its CPU at a fixed speed. Around 1980, computers ran at 4 Megahertz – now for the same money you can buy a 120 Megahertz computer. See also MEGAHERTZ.

Sockets CPU “Sockets” come in many different styles and configurations that tend to change with each successive generation of CPU. A socket is simply the place on the motherboard you “plug” the CPU into. Sockets often have simple names like “Slot 1” or “Slot 2” or seemingly incongruous names like “Socket 7” – these refer to the style of CPU that may be used.

Always make certain when purchasing a new CPU that it was designed to fit correctly in your motherboard’s CPU socket!

DIP SWITCHES

A DIP-switch is a tiny switch that, like a light switch, can be either on or off. Usually, DIP-switches aren’t found alone, but rather in block grouped together with other DIP-switches. Like jumpers, the purpose of a DIP-switch is to configure or setup your component to work in a specific way.

DRIVE INTERFACES

CACHE (DISK) A section of RAM that allows your computer to operate faster. Retrieving data from your hard disk is a slow process. A disk-caching program helps solve this problem by placing recently used data in your disk cache. Next time you need data, it may already be available in the disk cache, so a time-consuming search of the slow hard disk is avoided.

Integrated Drive Electronics (IDE) IDE is really a misnomer in the way we use it today because IDE refers to any drive with the controller built-in. The interface most of us use, what we call an IDE, is actually called ATA or AT Attachment. IDE drives are the most popular type of drives because the built-in controller eliminates many of the compatibility and configuration problems associated with SCSI drives. This coupled with the fact that IDE drives are generally inexpensive makes them a good choice for virtually any PC.

Serial ATA (SATA) Often abbreviated SATA or S-ATA, an evolution of the Parallel ATA physical storage interface. Serial ATA is a serial link — a single cable with a minimum of four wires creates a point-to-point connection between devices. Transfer rates for Serial ATA begin at 150MBps. One of the main design advantages of Serial ATA is that the thinner serial cables facilitate more efficient airflow inside a form factor and also allow for smaller chassis designs. In contrast, IDE cables used in parallel ATA systems are bulkier than Serial ATA cables and can only extend to 40cm long, while Serial ATA cables can extend up to one meter.

Serial ATA supports all ATA and ATAPI devices.

Small Computer Systems Interface (SCSI) SCSI is an entirely different interface than the more popular IDE. It is more of a system level interface, meaning that it does not only deal with disk drives. It is not a controller, like IDE, but a separate bus that is hooked to the system bus via a host adapter. A single SCSI bus can hold up to eight units, each with a different SCSI ID, ranging from 0 to 7. The host adapter takes up one ID, leaving 7 ID’s for other hardware. SCSI hardware typically consists of hard drives, tape drives, CD-ROMs and scanners. SCSI’s popularity is increasing – but its main problem is the lack of standards. Each company seems to have its own idea of how SCSI should work. While the connections themselves have been standardized, the actual driver specs used for communication have not been. The end result is that each piece of SCSI hardware has its own host adapter, and the software drivers for the device cannot work with an adapter made by someone else. So, due to the lack of an adapter standard, a standardized software interface, and standard BIOS for hard drives attached to the SCSI adapter, SCSI is pretty much a mess for the end-user.

FireWire (IEEE 1394) Another foray into high-speed interfaces is FireWire technology. Originally developed for the Macintosh, FireWire is steadily gaining in popularity with Windows users. FireWire’s high-speed interface is superior to IDE and overcomes the limitations of slower, traditional connections to external components using parallel or serial ports, including USB. FireWire is especially ideal for high-end graphics manipulation, including the transfer of data from digital video recorders to your hard drive. All Window’s version since Window’s 98 provide native support for FireWire technologies.

DRIVERS

Virtually all computer components require a software driver to operate. A driver is usually a small piece of software that tells your operating system (Windows) how to communicate properly with the component. Drivers are frequently updated by the manufacturer so you should periodically check their website for updates. An updated driver will often improve performance, overcome operating problems and often provide a new feature or two!

HARD DRIVE FILE SYSTEMS

There are several terms you should be familiar with in regards to formatting your hard drive. These include:

Partition A partition is how you divide the total available space on your hard drive. For example, if you have a 40 GB hard drive, instead of one large “C:\” drive you could partition it into smaller areas of data storage. In the past, before really large drives became available, partitioning was used to predefine an amount of space for a group of users. Another use is to create non-DOS partitions for different operating systems – for example, one partition may be used for Windows while another partition is used for OS2. With today’s technology, partitioning is really not quite so necessary as it once was.

Logical Drive A logical drive is the drive letter you assign to a partition. If you have four partitions, you would name them “C:\, D:\, E:\ and F:\” – any CD or DVD drives would automatically be assigned the next highest drive letter.

FAT (File Allocation Table) FAT has been the hard drive standard since 1981 with the first release of DOS. Simply put, FAT is the way DOS and early Window’s systems stored your files, using file names that were limited to 8 characters plus a 3-character extension.

FAT has a limitation of 2 GB partitions using large cluster sizes. This limitation makes using a FAT on a 40 GB hard drive almost impossible. All new Window’s operating systems still provide some level of support for FAT.

VFAT (Virtual File Allocation Table) VFAT is an extension of the FAT standard, introduce with Window’s 95. VFAT relaxed the FAT standard by allowing file names of up to 255 characters.

FAT32 (32 Bit Virtual File Allocation Table) FAT32 was released with the second version of Window’s 95 and was used in Window’s 98. FAT32 overcame the 2 GB partition limitations and reduced cluster sizes to a mere 4K.

NTFS (New Technology File System) NTFS was originally designed for Windows NT and provided support for features that other file systems lacked, such as a higher level of fault tolerance and better security and compression. Newer versions of Windows, such as Windows 2000 and Windows XP use NTFS in place of FAT32.

Another advantage to NTFS is the partition size – NTFS allows partitions up to 2 terabytes (2 trillion bytes)!

Compression Squeezing computer files into less space – compressed files are convenient because they allow you to store large, infrequently used files in a smaller area.

JUMPER SETTINGS

The term “jumper” gets tossed around a lot when it comes to upgrading computers. A jumper refers to both a small piece of plastic called a “shunt” that is used to connect two pins together and the pins themselves. Jumpers can be found everywhere including your motherboard, hard drive, CD-ROM drive and video card. The purpose of the jumpers is to configure or setup your component to work in a specific way.

For example, an AGP video card that is capable of running at two different speeds might have one jumper that tells it which speed you want to run it at. This jumper would consist of two tiny pins, standing side-by-side, somewhere on the video card. This jumper has two distinct states: open and closed. When open, the pins are exposed and physically not connected. When closed, the shunt is covering both pins, connecting them together. The video card itself is programmed to run at one speed when it is closed and at the other speed when it is open – this is the simplest form of a jumper. Hard drives take it up a notch by grouping 2 or 3 jumpers together. Most hard drives have 3 jumpers in a row, to make up a “block” of 6 pins. By shunting (also called “jumpering”) these pins in a variety of combinations, you can program the drive to act differently.

Jumpers are very straightforward and easy to understand; once you set your first jumper, you’ll know what we mean!

MEMORY TYPES

There are many different types of memory (RAM) that work with different generations of motherboards – in addition, memory modules have many different configurations, depending on their age and use so check the specifications carefully. Here are the most common styles:

SIMM – Single In-Line Memory Modules Used to be the most widely used memory and was available in 32 and 72 pin configurations. If you had an old 386/486 system, you probably used this type of memory.

DIMM – Dual In-Line Memory Modules As SIMM’s outgrew their usefulness, they were replaced by DIMM’s. These memory modules are available in a 168-pin configuration and transfer data in 64 bit chunks. If you have a laptop computer, these memory modules are called SO DIMM’s and are available in 72 and 144 pin configurations.

SDRAM – Synchronous DRAM memory Modules SDRAM actually synchronizes itself with the processor’s clock speed; allowing data transfer at speeds of up to 266 MHz. These are typically purchased as PC100 or PC133 modules, which denote the transfer rate.

RIMM – Direct Rambus Memory Modules The next generation of memory, RIMM’s are a trademark name for Direct Rambus technology. Available in a 180-pin configuration and transferring data at higher speeds, more heat is generated, so RIMM’s usually have an aluminum sheath (heat sink) around the exterior.

DDR – Double Data Rate Memory Modules The newest generation of memory, DDR’s are available in a wide configuration of speeds. As of this writing, transfer rates of 800 MHZ were available on the market – something you should definitely explore for your new motherboard!

DDR2 – Double Data Rate Memory (Version 2) Modules These modules are the next generation modules of memory in the DDR series. These are NOT the same as DDR, and will not work in generic DDR memory slots, they will work only in DDR2 specific motherboards. If your motherboard does not explicitly say DDR2, assume it is not. These modules are very fast, ranging in speeds from 800MHz to 1GHz+, but also cost more. The only problem is that these memory modules should be bought in pairs, as identical in pairs as you can get them. This makes their dual channel functionality show in flying colors. For example, two 512 MB DDR2 sticks would perform better than one single 1 GB DDR2 stick.

RDRAM – RAMBUS Memory Modules Another spin off next generation memory, RDRAM’s are available in a wide configuration of speeds. These are generally more expensive and sparsely supported.

CACHE (Memory) Two groups of extremely fast memory chips that allow your computer to operate faster. Internal cache (L1) is built into the CPU, and external cache (L2) resides on the motherboard. Both L1 and L2 store data recently used by the CPU. When the CPU needs data, it first checks the fastest source – L1. If the data is not there, the CPU checks the next-fastest source – L2. If the data still cannot be found, a time-consuming search of the slower RAM is required. Note: L2 cache is also called SRAM.

MOTHERBOARDS

Chipsets The chipset controls the system and its capabilities. All components communicate with the processor through the chipset – it is the hub of all data transfer. The chipset uses the DMA and the bus controllers to organize the steady flow of data that it controls. The chipset is a series of chips attached directly to the motherboard and is usually second in size only to the processor. Chipsets are integrated (soldered onto the motherboard) and are not upgradeable without a new motherboard.

FSB (Front Side Bus Speed) This is the speed at which the CPU communicates with the other components on the motherboard. As of this writing, you will probably see references to FSB’s anywhere from PC100 to 533 MHz.

Ports These are the various sockets located at the rear of your computer. You plug external components into these ports using an assortment of cables. These ports connect your monitor, printer, etc., to the motherboard.

PLUG AND PLAY

Plug and Play is an extremely beneficial technology for new users. In the past, you literally needed special training to be able to upgrade or replace computer components. This often involved not only changing the physical component, but included jumper changes, software installations and even manually reconfiguring the BIOS.

We recommend you always try to purchase Plug and Play components – these will give you the least amount of difficulty to install. With Plug and Play you literally “plug” in the new component and let your operating system take care of the details!

SLOT/BUS TYPES

There are four major slot types or buses:

Industry Standard Architecture (ISA) Used to be the most widely used bus, because it is the original. If you open up an old 286, you’ll see a couple of these. This bus is relatively slow, but cards such as modems do not require anything faster. If you look at your motherboard’s slots the longer, usually black ones, are the ISA’s. On newer machines, there might be only 1 or 2 ISA slots – the rest will be PCI. ISA is a very legacy slot.

Peripheral Component Interconnect (PCI) This is a very fast bus developed by Intel. The bus is self-configuring, which makes possible the plug-n-play concept in which each add-on card contains information about itself that the processor can use to automatically configure the card. This bus is by far the most popular on newer motherboards and PC’s. PCI slots are usually white in color and are shorter then ISA slots.

Peripheral Component Interconnect Express (PCI Express) This is a spin-off of the PCI bus, which competes with the AGP bus. Newer motherboards may come with one of these, instead of an AGP slot. Please note that these are not simply enhanced PCI slots, they are a totally new bus that is designed for video only. Normal PCI cards like network cards, sound cards, and the like will NOT work in a PCI-Express slot. PCI-Express is for video ONLY (at the time of writing), and is usually utilized by the newer nVidia brand video cards. ATi brand video cards tend to stick to the AGP slot. PCI Express will come in a variety specifications and slot sizes as it becomes more widely adopted. These are: PCI-Express X1, X4, X8, X16. Be sure to make your motherboard and PCI Express card comply with each other.

Accelerated Graphics Port (AGP) With newer software and games getting much more graphics intensive, the PCI bus is getting maxed out. In fact, the PCI bus, once considered very fast, could now be considered a bottleneck where graphics are concerned. In response, Intel designed the Accelerated Graphics Port, or AGP. In short, AGP uses the main PC memory to hold 3D images. In effect, this gives the AGP video card an unlimited amount of video memory. To speed up the data transfer, Intel designed the port as a direct path to the PC’s main memory. AGP is the latest craze in the need for graphical speed. The AGP slot is a short black slot and is the slot closest to your processor. ATi brand video cards stick to this slot.

Video Electronics Standard Association (VESA) This is an interface made mainly for video cards. VESA buses are basically an ISA slot with an extra slot on the end. The whole thing is about 4 inches longer than an ISA slot. Computer manufacturers in favor of the faster PCI bus have abandoned this design. Some older PC’s may have a couple of these slots. This, like ISA, is heavy depreciated.

Video Graphics Array (VGA) This is the general port on the back of your computer (coming from the motherboard or video card) that you plug the monitor into. It is usually blue and has 3 rows of 5 pin slots. Most monitors you encounter will use this interface, as it is the common standard as opposed to the newer DVI standard.

Digital Video Interface (DVI) This is the port on the back of your computer (coming from the motherboard or video card) that you can plug newer LCD monitors into. It is usually white and comes with 3 rows of 8 pin slots. You can even plug a high-definition television or projector into the DVI port with the proper converter!

USB (Universal Serial Bus)

A USB is an external bus (an interconnect) standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems and keyboards. Introduced in 1996, USB has completely replaced serial and parallel ports. It also supports plug-and-play installations and hot plugging Plug-and-play is the ability to add and remove devices to a computer while the computer is running and have the operating system automatically recognize the change. USB 2.0, which supports data transfer rates of 480 Mbps, was recently introduced as of this writing for Microsoft* Windows* XP.

Hot Swapping USB makes it possible to “Hot Swap” external components. This often means that you don’t need to shut down the computer, change the external component and then boot up again.

By vichhaiy Posted in SNA

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