Computer processors can handle millions of instructions each second. Once one instruction is processed, the next one in line is processed, and so on. A pipeline allows multiple instructions to be processed at the same time. While one stage of an instruction is being processed, other instructions may be undergoing processing at a different stage. Without a pipeline, each instruction would have to wait for the previous one to finish before it could even be accessed.
To understand the benefit of a pipeline, imagine that a car manufacturing plant had to wait for each car to be fully completed before starting on the next one. That would be horribly inefficient, right? It makes much more sense to work on many cars at once, completing them one stage at a time. This is what a pipeline in a computer allows. Pipelining, as it is called, often keeps around six instructions at once in the processor at different stages of processing. Pipelines can be used for the CPU as well as for accessing memory (DRAM).
The term “base station” was first used to refer to the towers you see on the side of the road that relay cell phone calls. These stations handle all cellular calls made within their area, receiving information from one end of the call and transmitting it to the other.
In the computer world, however, a base station refers to the wireless access point for computers with wireless cards. It is basically a router that communicates with devices based on the Wi-Fi standard. Some common Wi-Fi configurations include 802.11b and 802.11g. Wireless base stations are made by companies such as Netgear, Linksys, D-Link, Apple Computer, and other manufacturers. Fortunately, as long as the hardware is based on the Wi-Fi standard, all wireless cards can communicate with base stations from any manufacturer.
A wiki is a Web site that allows users to add and update content on the site using their own Web browser. This is made possible by Wiki software that runs on the Web server. Wikis end up being created mainly by a collaborative effort of the site visitors. A great example of a large wiki is the Wikipedia, a free encyclopedia in many languages that anyone can edit. The term “wiki” comes from the Hawaiian phrase, “wiki wiki,” which means “super fast.” I guess if you have thousands of users adding content to a Web site on a regular basis, the site could grow “super fast.”
Stands for “Secure Digital.” It is a type of memory card used for storing data in devices such as digital cameras, PDAs, mobile phones, portable music players, and digital voice recorders. The card is one of the smaller memory card formats, measuring 24mm wide by 32mm long and is just 2.1mm thick. To give the cards some orientation, the top-rght corner of each SD card is slanted. Even though the cards are extremely small, as of late 2004, they can hold up to 8GB of data.
Part of the reason the cards are called “Secure Digital” cards is because the cards have a copyright protection feature built in. The security feature, called “key revocation” means protected data on the card can only be read by specific devices. The cards can have both secured and unsecured areas on them for copyrighted and non-copyrighted data. For more information on SD cards, visit the SD Card Association.
Safe Mode is a way for the Windows operating system to run with the minimum system files necessary. It uses a generic VGA display driver instead of the vendor-specific driver, which means you will likely be working with only 16 colors in a resolution of 640×480. Safe Mode also turns off all third-party drivers for other peripherals such as mice, keyboards, printers, and scanners. In basic Safe Mode, networking files and settings are not loaded, meaning you won’t be able to connect to the Internet or other computers on a network.
So why would I ever want to boot in Safe Mode? Well, that’s a good question. Sometimes, Windows may not fully load after an unexpected crash and the only way to get the computer to boot is to use Safe Mode. Once you have successfully booted the computer in Safe Mode, you can run a disk utility program to repair corrupted files or directories on the hard drive. You can also reboot into Safe Mode to see your display when you get a “Sync Out of Range” message on your screen.
There may also be times when your computer is performing sluggishly and becomes annoyingly slow. Booting into Safe Mode will allow you to diagnose the problem and determine which files are slowing down the computer. When calling technical support, the support person may ask you to boot into Safe Mode to begin the troubleshooting. To boot your Windows computer into Safe Mode, hold down the F8 key while the computer is starting up. Then select Safe Mode from the list of boot options.
Stands for “Standard RGB” (and RGB stands for Red-Green-Blue”). All the colors you see on your computer display are made up various mixtures of red, green, and blue light. While this works great for individual displays, the same colors are often displayed differently on different screens. For example, dark red on one screen may look like red-orange on another. When you add printers, scanners, and digital cameras to the mix, the problem is magnified even more.
To help achieve a greater color consistency between hardware devices, the sRGB standard was created in 1999. It defines a gamut of colors that represents each color well and can be used by CRT monitors, LCD screens, scanners, printers, and digital cameras. It also has been incorporated into many Web browsers to make sure the colors on Web pages match the color scheme of the operating system. Because of the color consistency sRGB creates, most hardware devices that work with images now use it as the default setting.
The controller card, or simply “controller,” is a piece of hardware that acts as the interface between the motherboard and the other components of the computer. For example, hard drives, optical drives, printers, keyboards, and mice all require controllers to work. Most computers have all the necessary controllers built in the motherboard as chips, not full-sized cards. However, if you add additional components such as a SCSI hard drive, you may need to add a controller card as well. Controller cards are typically installed in one of the computer’s PCI slots.
Stands for “Advanced Interactive Executive,” though some Linux fans have been known to refer to it as “Ain’t UNIX.” AIX is an operating system developed by IBM and is in fact Unix-based. It is typically used for enterprise servers and comes with a robust set of security options such as Kerberos V5 network authentication and dynamic secure tunnel authentication. AIX allows the system administrator to divide memory, CPU, and disk access between various jobs. The system supports IBM’s 64-bit POWER processor and is backwards-compatible with 32-bit applications. It also runs most Linux applications (after recompiling them) and has full support for Java 2. If all that jargon makes no sense to you, relax — AIX is not your typical consumer operating system. It is mainly used for servers in large businesses where IT geeks get to work with it.
Stands for “Zero Insertion Force.” ZIF is a type of CPU socket on a computer motherboard that allows for the simple replacement or upgrade of the processor. Processors that use a ZIF socket can easily be removed by pulling a small release lever next to the processor and lifting it out. The replacement processor is then placed in the socket and secured by pushing the lever in the opposite direction — hence the phrase, “zero insertion force.” I suppose there is some force required to push the lever, but it is significantly less than non-ZIF sockets, which require special tools to force the processor out.
Blu-ray is an optical disc format such as CD and DVD. It was developed for recording and playing back high-definition (HD) video and for storing large amounts of data. While a CD can hold 700 MB of data and a basic DVD can hold 4.7 GB of data, a single Blu-ray disc can hold up to 25 GB of data. Even a double sided, dual layer DVD (which are not common) can only hold 17 GB of data. Dual-layer Blu-ray discs will be able to store 50 GB of data. That is equivalent to 4 hours of HDTV.
Blu-ray discs can hold more information than other optical media because of the blue lasers the drives use. The laser is actually blue-violet, but “Blu-ray” rolls off the tounge a little easier than “Blu-violet-ray.” The blue-violet laser has a shorter wavelength than the red lasers used for CDs and DVDs (405nm compared to 650nm). This allows the laser to focus on a smaller area, which makes it possible to cram significantly more data on a disc the same size as a CD or DVD. Proponents of the Blu-ray format say they expect Blu-ray devices to replace VCRs (thank goodness) and DVD recorders as more people make the transition to HDTV.