Computer Learning (part 3)

Computer Acronyms definitions
AGP (Accelerated Graphics Port)
Stands for "Accelerated Graphics Port." AGP is a type of expansion slot designed specifically for graphics cards. It was developed in 1996 as an alternative to the PCI standard. Since the AGP interface provides a dedicated bus for graphics data, AGP cards are able to render graphics faster than comparable PCI graphics cards.

Like PCI slots, AGP slots are built into a computer'smotherboard. They have a similar form factor to PCI slots, but can only be used for graphics cards. Additionally, several AGP specifications exist, including AGP 1.0, 2.0, and 3.0, which each use a different voltage. Therefore, AGP cards must be compatible with the specification of the AGP slot they are installed in.

Since AGP cards require an expansion slot, they can only be used in desktop computers. While AGP was popular for about a decade, the technology has been superseded by PCI Express, which was introduced in 2004. For a few years, many desktop computers included both AGP and PCI Express slots, but eventually AGP slots were removed completely. Therefore, most desktop computers manufactured after 2006 do not include an AGP slot.


BASIC (Beginner's All-purpose Symbolic Instruction Code)
Stands for "Beginner's All-purpose Symbolic Instruction Code." BASIC is a computer programming language that was developed in the mid-1960s to provide a way for students to write simple computer programs. Since then, the language has evolved into a more robust and powerful language and can be used to create advanced programs for today's computer systems.

BASIC originally used numbers at the beginning of each instruction (or line) to tell the computer what order to process the instructions. Lines would be numbered as 10, 20, 30, etc., which would allow additional instructions to be placed between commands later on if needed. "GOTO" statements enabled programs to loop back to earlier instructions during execution. For example, line 230 of a BASIC program may have an "if" clause that tells the computer to jump back to line 50 if a variable is less than 10. This instruction might look something like this:

230 IF (N < 10) THEN GOTO 50

More modern BASIC implementations use "while loops," which perform a series of instructions as long as a certain case is true. Newer BASIC development software also supports more data types, such as integers, strings, and arrays, for storing variables and other data. While the first BASIC development environments were strictly text-based, today's BASIC programming software allows developers to design much of their programs visually, using a graphical user interface. Some of the more popular BASIC development programs used today include REALbasic and Microsoft Visual Basic.


DDR2 (Double Data Rate 2)
Stands for "Double Data Rate 2." DDR2 RAM is an improved version of
 DDR memory that is faster and more efficient. Like standard DDR memory, DDR2 memory can send data on both the rising and falling edges of the processor's clock cycles. This nearly doubles the amount of work the RAM can do in a given amount of time. DDR and DDR2 are also both types of SDRAM, which allows them to run faster than conventional memory.

While DDR and DDR2 have many similarities, DDR2 RAM uses a different design than DDR memory. The improved design allows DDR2 RAM to run faster than standard DDR memory. The modified design also gives the RAM morebandwidth, which means more data can be passed through the RAM chip at one time. This increases the efficiency of the memory. Since DDR2 runs more efficiently than standard DDR memory, it actually uses less power than DDR memory, even though it runs faster. The only downside of DDR2 memory is that it is not compatible with standard DDR slots. So make sure your computer supports DDR2 RAM before upgrading your memory.


DSLAM (Digital Subscriber Line Access Multiplexer)
Stands for "Digital Subscriber Line Access Multiplexer." A DSLAM is a device used by Internet Service Providers (ISPs) to route incoming DSL connections to the Internet. Since a "multiplexer" combines multiple signals into one, a DSLAM combines a group of subscribers' connections into one aggregate Internet connection.

For example, a DSL access multiplier may receive signals from all the DSL modems in a certain neighborhood and patch them through to the Internet backbone. The DSLAM processes each incoming connection and may limit thebandwidth of certain DSL lines. Most DSL service providers use multiple DSLAMs to help route incoming and outgoing traffic in the most efficient way possible.


CDMA (Code Division Multiple Access)
Stands for "Code Division Multiple Access." CDMA is a wireless transmission technology that was developed during World War II by the English allies to avoid having their transmissions jammed. After the war ended, Qualcomm patented the technology and made it commercially available as a digital cellular technology. Now CDMA is a popular communications method used by many cell phone companies.

Unlike the GSM and TDMA technologies, CDMA transmits over the entire frequency range available. It does not assign a specific frequency to each user on the communications network. This method, called multiplexing, is what made the transmissions difficult to jam during World War II. Because CDMA does not limit each user's frequency range, there is more bandwidth available. This allows more users to communicate on the same network at one time than if each user was allotted a specific frequency range.

Because CDMA is a digital technology, analog audio signals must be digitized before being transmitted on the network. CDMA is used by 2G and 3G wireless communications and typically operates in the frequency range of 800 MHz to 1.9 GHz.