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Computer, Telephony & Electronics
Industry Glossary
10Base-2
At the time of this writing, June 1996, this is the most widely used form of networking backbone architecture. The structure is Ethernet; the 10 indicates 10 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The 2 indicates it is a coaxial cable, usually RG-58 (52 ohm cable often known as thin net), with BNC type connectors on the ends. The maximum segment is published to be 185 meters although with quality RG58au cable and good connections, it can easily support distances of 300 meters, repeaters and amplifier hubs can be used to join segments and increase the overall distance covered by the network. 10Base-5 is similar.
10Base-5
At the time of this writing, June 1996, this is the least widely used form of networking backbone architecture, because it is cumbersome and awkward to work with. The structure is Ethernet; the 10 indicates 10 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The 5 indicates it is a coaxial cable (there are several RG identifiers to the cable, the most common of which is RG-6, often known as thick net, fat-dat or sewer pipe). The maximum segment is published to be 500 meters but with good connections, it can easily support distances of 700 meters; repeaters and amplifier hubs can be used to join segments and increase the overall distance covered by the network. This cable is seldom used any more because of the trouble and expense involved with it. It is UGLY and difficult to hide (sort of like a MAC)! 10Base-2 is similar.
10Base-F
This is the reliable and current state of the art network cable architecture. The structure is Ethernet; the 10 indicates 10 megabits per second transfer rate, or speed of the net; however, recent advances make this an incorrect rate. Point to point connections often approach 1000 megabits per second (1 Gigabit) between capable routers and switches. The Base means a baseband network but it is used in broadband also and supports a much wider bandwidth than other Ethernet connectors. The F indicates it is a fiberoptic cable and includes subcategories of 10Base-FB, 10Base-FL and 10Base-FP. The maximum segment is published to be 5000 meters but under most circumstances with a contiguous cable and good connections, it can easily support huge distances, miles between connections, and repeaters and amplifier hubs can be used to join segments and increase the overall distance covered by the network. This cable is difficult to manage and work with but is very reliable. The downside is the trouble and expense involved with it. It is the backbone structure of the Internet. Although used primarily as a device to device pathway, such as a backbone, it is finding some situations where even stations are connected to this for maximum bandwidth and speed. Need a representative table of various comparative speeds? See SONET.
10Base-FB
10 megabits per second baseband Ethernet specification using fiberoptic cabling. 10Base-FB is a subcategory of the IEEE 10Base-F specification. Published 10Base-FB segments can be up to 1.24 miles (2000 meters). It is not used to connect user stations, but instead provides a synchronous signaling backbone that allows additional segments and repeaters to be connected to the network. In many circumstances, those distances can be doubled in practical use.
10Base-FL
10 megabits per second baseband Ethernet specification using fiberoptic cabling. 10Base-FL is a subcategory of the IEEE 10Base-F specification and, while able to function with FOIRL, is designed to replace the FOIRL specification. Published 10Base-FL segments can be up to 3280 feet (1000 meters) long if used with FOIRL, and up to 1.24 miles (2000 meters) if 10Base-FL is used exclusively. In many circumstances, those distances can be doubled in practical use.
10Base-FP
10 megabits per second baseband Ethernet specification using fiberoptic cabling. 10Base-FP is a subcategory of the IEEE 10Base-F specification. Published 10Base-FP segments can be up to 1640 feet (500 meters) long. It organizes a number of computers into a star network topology without the required use of repeaters. In many circumstances, those distances can be doubled in practical use.
10Base-T
This is the most widely used form of networking cable architecture. The structure is Ethernet; the 10 indicates 10 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The T indicates a twisted pair of wires connected the transmit and receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes two pairs of twisted cable for one connection, four wires. Each transmit is twisted with the other transmit wire and each receive is twisted with the other receive wire. The more twists the better the performance as a common rule. The connectors used are most often RJ-45s but can be RJ-11s under certain requirements. The maximum segment is published to be 100 meters although with quality CAT 5 cable and good connections, it can easily support distances of 300 meters. 100Base T is similar.
10Broad-36
As of this writing, June 1997, this is THE most obscure form of networking backbone architecture, because it is expensive, cumbersome and awkward to work with. It is now virtually obsolete. The structure is Ethernet; the 10 indicates 10 megabits per second transfer rate, or speed of the net. The Broad means a broadband coaxial cable network, or segment. The 36 indicates it is a wide bandwidth coaxial cable. The maximum segment is published to be 300 meters but with good connections and minimal bandwidth throughput, it can easily support distances of 1000 meters; special broadband repeaters and broadband amplifier hubs can be used to join segments and increase the overall distance covered by the network. This cable is seldom used any more because of the trouble and expense involved with it. It is designed for bandwidth, not distance and has more or less been replaced by several better technologies.
100Base-FX
100 megabits per second baseband Ethernet specification using fiberoptic cabling. 100Base-FX is a category of the IEEE 10Base-T specification, even though it is not a twisted pair design. Published 100Base-FX segments can be up to (400 meters) but to guarantee proper signal timing, a 100BaseFX link cannot exceed that. It is not used to connect user stations, but instead provides a unique junction using two strands of multimode fiber-optic cable per link to be connected to the network.
100Base-T
This is the current technology, January 2000, used in the widely used twisted pair form of networking cable architecture. The structure is Ethernet; the 100 indicates 100 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The T indicates a twisted pair of wires connected the transmit and receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes two pairs of twisted cable for one connection, four wires. Each transmit is twisted with the other transmit wire and each receive is twisted with the other receive wire. The more twists the better the performance as a common rule. The connectors used are most often RJ-45s but can be RJ-11s under certain requirements. This is also known as FastEthernet. The maximum segment is published to be 100 meters although with quality CAT 5 or CAT 6 cable and good connections, it can often support distances of 150 meters. It is used most often as a higher performance version of 10Base-T and can co-exist in the same network if the proper concentrators, bridges, hubs and switches are present. Most network managers agree that the actual throughput difference on a busy network is usually 1.5 to 2 times faster than 10Base T, not the 10 times you would expect from the specifications. With no 10Base-T switches or sensing NICs on the network, the throughput increase is somewhat higher but seldom exceeds 3 times faster than 10Base-T overall.
100Base-T4
This is one of the current, March 2001, technologies used in the widely used twisted pair form of networking cable architecture. The structure is Ethernet; the 100 indicates 100 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The T indicates a twisted pair of wires. The 4 means 4 pairs of wires, instead of the normal 2 pairs. For a connection, in that two pair of wires is connected the transmit and another two pair to the receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes four pairs of twisted cable for one connection, eight wires. Each transmit pair is twisted with the other transmit pair and each receive pair is twisted with the other receive pair. The more twists the better the performance as a common rule. The connectors used are RJ-45s. This is also known as FastEthernet4. The maximum segment is published to be 100 meters although with quality CAT 3, CAT 4, CAT 5 or CAT 6 UTP cable and good connections, it can often support distances of 150 meters. It is used most often as a higher performance version of 10Base-T and can co-exist in the same network if the proper concentrators, bridges and switches are present. Most network managers agree that the actual throughput difference on a busy network is usually 1.5 to 2 times faster than 10Base T, not the 10 times you would expect from the specifications. With no 10Base-T switches or sensing NICs on the network, the throughput increase is somewhat higher but seldom exceeds 3 times faster than 10Base-T overall. This technology is excellent for utilization of older wiring already in place.
100Base-TX
This is a current, March 2001, technology used in the widely used twisted pair form of networking cable architecture. The structure is Ethernet; the 100 indicates 100 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The T indicates a twisted pair of wires. The X means extended specification in that two pair of wires is connected the transmit and another two pair to the receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes four pairs of twisted cable for one connection, eight wires. Each transmit pair is twisted with the other transmit pair and each receive pair is twisted with the other receive pair. The more twists the better the performance as a common rule. The connectors used are RJ-45s. This is also known as FastEthernetX. The maximum segment is published to be 100 meters although with quality CAT 5 or CAT 6 UTP or STP cable and good connections, it can often support distances of 150 meters. It is used most often as a higher performance version of 10Base-T and can co-exist in the same network if the proper concentrators, bridges and switches are present. Most network managers agree that the actual throughput difference on a busy network is usually 1.5 to 2 times faster than 10Base T, not the 10 times you would expect from the specifications. With no 10Base-T switches or sensing NICs on the network, the throughput increase is somewhat higher but seldom exceeds 3 times faster than 10Base-T overall. This technology is excellent for speed in electrically noisy environments.
100Base-VG
This is a proprietary designed (June 2001) and used form of networking cable architecture. The design is by HP and AT&T. The structure is Ethernet, though non-standard; the 100 indicates 100 megabits per second transfer rate, or speed of the net. The Base means a baseband network. The VG (Virtual Graphic) indicates a twisted pair of wires (capable of graphic support) connected the transmit and receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes four pairs of twisted cable for one connection, eight wires. Each transmit primary and transmit secondary is twisted with the other transmit wire and each receive primary and receive secondary is twisted with the other receive wire. The more twists the better the performance as a common rule. The connectors used are most often RJ-45s but can be RJ-11s under certain requirements. This is also known as FastEthernet. The maximum segment is published to be 100 meters although with quality CAT 3 or better cable (mostly CAT 5 or CAT 6) and good connections, it can often support distances of 200 meters. It can co-exist in a standard Ethernet network only if the proper concentrators, bridges and switches are present. This has not been adopted by many other companies and is only used where mass amounts of multimedia information travel from port to port. This technology is excellent for utilization of older wiring already in place.
100Base-VG-AnyLan
This is an adaptation of 100Base VG, the proprietary designed and used form of networking cable architecture. The original design is by HP and AT&T. The newer structure (August 2001) is also Ethernet capable, but can be used with token ring or any other TP supported network. The 100 indicates 100 megabits per second transfer rate, or the speed of the net. The Base means a baseband network. The VG (Virtual Graphic) indicates a twisted pair of wires (capable of graphic support) connected the transmit and receive ports of the hub and or NICs. The wires can be shielded STP or unshielded UTP and it takes four pairs of twisted cable for one connection, eight wires. Each transmit primary and transmit secondary is twisted with the other transmit wire and each receive primary and receive secondary is twisted with the other receive wire. The more twists the better the performance as a common rule. The connectors used are RJ-45s. This is also known as AnyLan. The maximum segment is published to be 100 meters although with quality CAT 3 or better cable (mostly Cat 5) and good connections, it can often support distances of 200 meters. It can co-exist in a standard Ethernet network only if the proper concentrators, bridges and switches are present. This has not been adopted by many other companies and is only used where mass amounts of multimedia information travel from port to port, within a multiple topology network. This technology is excellent for utilization of older wiring already in place.
1000Base-T
This is the current, January 2006, technology used in the widely used twisted pair form of networking cable architecture. The structure is Ethernet; the 1000 indicates 1000 megabits per second transfer rate (also called gigabit), or speed of the net. The Base means a baseband network. The T indicates a twisted pair of wires connected the transmit and receive ports of the hubs, routers or switches. This connection does not go directly to NICs. There are several special chassis connection units, the equivalent of a super NIC, for high end servers to use. The wires can be shielded STP or unshielded UTP and it takes two pairs of twisted cable for one connection, four wires. Each transmit is twisted with the other transmit wire and each receive is twisted with the other receive wire. The more twists the better the performance as a common rule. The connectors used are most often RJ-45s but can be custom under certain requirements. This is also known as UltraFastEthernet. 3COM is the pioneer in gigabit over copper technology. According to them, the maximum segment is 60 meters although, again, according to 3COM, with quality CAT 5 or CAT 6 cable and good connections, it can support distances of 100 meters. It is used most often as a junction to other Ethernet networks and a higher performance version of 100Base-T and 10Base-T that can co-exist in the same network if the proper concentrators, bridges and switches are present. (3COM just happens to make them!) Most network managers (that are lucky enough to have these) agree that the actual throughput difference on a busy network is usually 10 to 20 times faster than 10Base T, not the 100 times you would expect from the specifications. This is a hybrid joining technology that would not be used if there were not other copper Ethernet networks present.
110 block
A telephony term. A terminal block where up to 4 sets of up to 25 pairs of wire can be interconnected. The installer uses a special "punch down" tool to connect the wires. The number indicated the spacing of terminals on the block. The other popular spacing is on a 66 block.
2G
An abbreviation for Second Generation. In technology circles, advancements are measured in generations. Why? Don't ask 'cause I don't know. Anyway, 2G is advanced and should be a much better product than the first generation. Also see 3G and 4G.
3270
The numeric designation that was given by IBM to the most popular of the IBM large frame terminals. Today, some 30 years after, it is still the standard of the industry for terminals. It is a non-programable terminal interface (used by systems such as IBM IMS, BellCore SMS, CICS, and similar packages). PC 3270 emulation software is available for smaller PCs wanting to attach to a large frame computer. 3270 screen formating is done by a host computing system.
386
The common abbreviation for the Intel 80386 processor.
3COM
An industry giant in the modem, router, networking and telecommunication segments of the computer and telephony world. The former US Robotics company, a pioneer in the modem industry, is now part of 3COM.
3D audio
A technique for giving more depth to traditional stereo sound. Typically, 3-D sound, or 3-D audio, is produced by placing a device in a room with stereo speakers. The device dynamically analyzes the sound coming from the speakers and sends feedback to the sound system so that it can re-adjust the sound to give the impression that the speakers are further apart. 3-D audio devices are particularly popular for improving computer audio where the speakers tend to be small and close together. There are a number of 3-D audio devices that attach to a computer's sound card. This is not the same as Surround Sound normally associated with Dolby Digital (AC-3). See audio.
3D NOW
A technique from AMD that enable very rapid 3D representation of graphics via pipeline hardware. The technology involves 21 instructions that are similar to the 21 MMX instructions from Intel. While the Intel MMX architecture is integer intensive, the MAD 3D NOW architecture is floating point intensive. The company claims that in the same time MMX does 2D representation, the 3D NOW instructions do 3D representations.
3G
An abbreviation for Third Generation. In technology circles, advancements are measured in generations. Why? Don't ask 'cause I don't know. Anyway, 3G is fairly advanced and should be a stable and healthy product in either hardware or software. Not to be confused with G3. Also see 2G and 4G.
.3GR files
Files that allow Windows operating systems to display text and graphics in enhanced mode on an Intel (or compatible) 80386 or higher computer.
404
An error code, in fact, the most common error on the Internet. It is a "file not found" error. The reason can be that you misspelled the file or something in the URL, or could be that it does not exist. It does not mean that it never did; it could be that it it just down for a moment or down for good. You must determine that be checking back or finding out from other sources.
4004
One of Intel's family of microprocessors; introduced in 1971. It had a clock speed of 108 Khz and a 4 bit bus.
486
The common abbreviation for the Intel 80486 processor.
4bone
See IPv4 and IP.
4G
An abbreviation for Fourth Generation. In technology circles, advancements are measured in generations. Why? Don't ask 'cause I don't know. Anyway, 4G and beyond is very advanced and should be an exceptionally stable and healthy product in either hardware or software. To my knowledge, there are no efforts to distinguish technologies above the 4G level. Also see 2G and 3G.
4mm tape
This is a common backup media also known as DAT (Digital Audio Tape) within the industry. This popular format was invented by SONY and is licensed to many tape manufacturers. Capacities are generally between 2 and 24GB. The transfer rate differs from company to company and based on the controller can be up to about 3MB per second. This format offers reasonably good performance at a good price and the cartridge is small and easy to store. The cartridge size is 2.9"x2.1"x.4" total. See 8mm tape.
555
A clock timer chip, made originally by Signetics, but now manufactured in various types by several companies. We have several 555 calculators on our site but there are many GREAT 555 sites from which you can gather much knowledge. Check the electronics selections for the latest. Try National Semiconductor's Information Page and Iguanalabs.Com.
556
A dual clock timer chip version of the 555, made originally by Signetics. See 555.
558
A quad clock timer chip version of the 555, made originally by Signetics. See 555.
6bone
See IPv6 and IP.
66 block
A telephony term. A terminal block where up to 4 sets of up to 25 pairs of wire can be interconnected. The installer uses a special "punch down" tool to connect the wires. The number indicated the spacing of terminals on the block. The other popular spacing is on a 110 block.
6800
One of Motorola's family of microprocessors; introduced in 1974. It had clock speeds of 1 and 2 Mhz and an 8 bit bus.
6802
One of Motorola's family of microprocessors; introduced in 1974. It had clock speeds of 1 and 2 Mhz and an 8 bit bus. Second sourced by Hitachi. Had a 256 byte scratch pad within.
6809
One of Motorola's family of microprocessors; introduced in 1974. It had clock speeds of 1 and 2 Mhz and an 8 bit bus. Had an external clock input for sync opteration to external components. Was used in the original Apple.
68000
One of Motorola's family of microprocessors; introduced in 1979. It had a clock speed of 6 Mhz and a 16 bit bus.
8008
One of Intel's family of microprocessors; introduced in 1972. It had a clock speed of 200 Khz and an 8 bit bus.
802
A set of network standards developed by the IEEE. They include but are not limited to the following group.
IEEE 802.1: Standards related to network management.
IEEE 802.2: General standard for the data link layer in the OSI Reference Model. The IEEE divides this layer into two sublayers, the logical link control (LLC) layer and the media access control (MAC) layer. The MAC layer varies for different network types and is defined by standards IEEE 802.3 through IEEE 802.5.
IEEE 802.3: Defines the MAC layer for bus networks that use CSMA/CD. This is the basis of the Ethernet standard.
IEEE 802.4: Defines the MAC layer for bus networks that use a token-passing mechanism (token bus networks).
IEEE 802.5: Defines the MAC layer for token-ring networks.
IEEE 802.6: Standard for Metropolitan Area Networks (MANs).
802.11
802.11 refers to a family of specifications developed by the IEEE for wireless LAN technology. 802.11 specifies an over-the-air interface between a wireless client and a base station or between two wireless clients. The IEEE accepted the specification in 1997.
There are several specifications in the 802.11 family:
802.11 relates to wireless LANs (WLANs) and provides 1 or 2 Mbps transmission in the 2.4 GHz band using either frequency hopping spread spectrum (FHSS) or direct sequence spread spectrum (DSSS).
802.11a is an extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5GHz band. 802.11a uses an orthogonal frequency division multiplexing encoding scheme rather than FHSS or DSSS. While an older specification, it has not been popular. However, it seems to be perhaps slightly more secure because of it and less susceptible to interference because of the frequency.
802.11b (also referred to as 802.11 High Rate or WI-FI), is an extension to 802.11 that applies to wireless LANS and provides 11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band. 802.11b uses only DSSS. 802.11b was a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.
802.11c provided documentation of 802.11-specific MAC procedures to the ISO/IEC. 802.11d provided definitions and requirements to allow the 802.11 standard to operate in countries not currently served by the standard.
802.11g relates to wireless LANs and provides 54+ Mbps in the 2.4 GHz and in some cases of compatibility with 802.11a, the 5.8 GHz bands. Some are backwards compatible with either A or B and some are not; generally G is backward compatible with B. (TANS).
As of January 2005, the proposed 802.11h and 802.11i have not been accepted and utilized; however as of January 2006, 802.11n is well on its way and is better defined. It is partially backward compatible with A, B and G, combining multiple input/multiple output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) technologies to increase throughput. It will also use some of the technologies from both to base a 100Mbps platform. Several of the previously announced specifications of 802.11n were also tabled for the time being, due to the vast number of variations proposed; it is also said that the standard specifications is based around the Airgo Networks' True MIMO chipsets. Rumor has it that the discarded proposals will surface again in the next generation of the 802.11 specification. TANS strikes again!
80286
One of Intel's family of microprocessors; introduced in 1982. It had clock speeds of 6, 8, 10 and 12.5 Mhz and a 16 bit bus.
80287
One of Intel's family of math coprocessors; introduced in 1982. It had clock speeds of 6, 8, 10 and 12.5 Mhz, which had to match the processor.
80386
One of Intel's family of microprocessors; introduced in 1985. It had clock speeds of 16, 20, 25 and 33 Mhz. In the SX design, it had a 16 bit bus but in the DX configuration had a 32 bit bus. The SX did not have an onboard math coprocessor.
80387
One of Intel's family of math coprocessors; introduced in 1985. It had clock speeds of 16, 20, 25 and 33 Mhz, which had to match the processor.
80486
One of Intel's family of microprocessors; introduced in 1989. In the DX configuration, it had clock speeds of 25, 33 and 50 Mhz and a 32 bit bus. The SX configuration also offered a 16 Mhz clock speed. The SX did not have an onboard math coprocessor.
80487
One of Intel's family of math coprocessors; introduced in 1989. In the DX configuration, it had clock speeds of 25, 33 and 50 Mhz, which had to match the processor.
8080
One of Intel's family of microprocessors; introduced in 1974. This was the brain of the first popular microcomputer. It had a clock speed of 2 Mhz and an 8 bit bus.
8086
One of Intel's family of microprocessors; introduced in 1977. It had clock speeds of 5, 8 and 10 Mhz and a 16 bit bus.
8088
One of Intel's family of microprocessors; introduced in 1978. It had clock speeds of 5 and 8 Mhz and an 8 bit bus.
8-bit-clean
A slang term meaning that the "data is fully encrypted". Each byte, all 8 bits, is handled in a manner to fully code it for transmission. See BINHEX.
8mm tape
This is a similar but more advanced backup media to DAT (4mm tape). This popular format was also invented by SONY and is licensed to many tape manufacturers. Capacities are generally between 7 and 60GB. The transfer rate differs from company to company and based on the controller can be up to about 6MB per second. This format offers very good performance at a good price and the cartridge is also small and easy to store. The cartridge size is 3.75"x2.5"x.5" total. The media is NOT interchangable or backward compatible with 4mm DAT.
9445
One of Fairchild's family of microprocessors (CPUs); introduced in 1983. It had clock speeds of 5 and 8 Mhz and a 16 bit bus, though it was an octal machine brain. It was originally designed to military specifications with a Data General (DG, now EMC) Nova instruction set. We wrote the original Operating system for this for NASA.
. or dot
. is pronounced DOT. It is a separator in file and URL names and addresses.
.AAC files
The file name extension for Advanced Audio Coding. A protected version of the AAC file format is used by iTunes Music Store. Protected AAC files bought from iTunes Music Store can only be used on IPODs (or iPODs, or iPods) and the IPOD cannot use songs bought from any other music downloading service. AAC is the default audio format for songs ripped from CDs in iTunes. AAC was developed by a number of companies, including Sony and Dolby, to replace MP3, and as of 2005, is the digital audio standard. It is a lossy file format, which means that AAC files are compressed, resulting in smaller file sizes.
.AFM files
Files that are PostScript font metrics and data
for the Font Foundry program from Adobe. Get more information at HTTP://WWW.ADOBE.COM.
.AIF or .IEF files
The file extensions for AIFF type files, short for Audio Interchange File Format, a common format for storing and transmitting sampled sound. The format was developed by Apple Computer and is the standard audio format for Macintosh computers. It is also used by Silicon Graphics Incorporated (SGI). The format encodes audio data in 8-bit mono or stereo waveforms. AIFF files generally end with a .AIF or .IEF extension. The AIFF format does not support data compression so AIFF files tend to be large. However, there is another format called AIIF-Compressed (AIFF-C or AIFC) that supports compression rations as high as 6:1. See audio.
.ARC files
Files that are compressed using the program ARC (Most ISP's Windows software will decompress these files.)
.ARJ files
Files compressed using a version of the ARC compression algorithm.
.ART files
These are graphics that are compressed using the Johnson-Grace compression scheme. This is a lossy compression, but allows files to be transferred very quickly. Most ISP's software can view these files.
.ASC files
These are files that contain only ASCII characters. The files are also often called text files with the extension .TXT. You can see the ASCII codes and what they do.
.ASP files
The file extension for Microsoft's Active Server Pages, ASP.
.ASPX files
The file extension for Microsoft's Active Server Extended Pages, ASP.
.ASP+ files
The file extension for Microsoft's Active Server Pages +, ASP, also known as ASP.NET.
.au or .AU files
.au files are audio files, commonly used on UNIX workstations. See audio.
.AVI files
These are Windows-based audio and visual files, and can be viewed by using most ISP software. (Proper Windows drivers must be installed.) See audio.
.BAT files
These are batch files, or scripts run in DOS that are designed to automate tasks. They are the equivalent of a DOS macro command language.
.BMP files
This is a Windows bitmap file, a type of graphics file used by Windows for backgrounds. Windows wall paper is a bitmap image. See bitmap.
.CGM files
These are graphics files for Windows use. The acronym is for Computer Graphics Metafile (CGM). It is an ANSI standard format for exchanging graphics files between applications, in both vector and raster formats. It has been outdated by the use of more easily used and more common formats.
.COM files
These are small programs for DOS; usually utilities. They are used the same as .EXE files but have specific non-relocatable addresses.
.CPT files
These are Macintosh files that have been compressed using the Compact Pro compression format. See Apple.
.CRD files
These are Windows files that are associated with any card system or card file.
.DLL files
Dynamic Link Library, these files give functionality to other programs. They usually need to be installed into the WINDOWS/SYSTEM directory. VBRUN300.DLL is a good example; it is needed for Visual Basic 3.0 created programs. Windows version W95, W98 & NT are built with them. See DLL.
.DOC files
Documents, this is the default file extension for Microsoft Word. At present, Word is included in the Microsoft Office Suite. Most files with this extension will be Microsoft Word files, but there are many that are plain text. Also the name of the person you go see when you have been working with computers for too long.
.DOT files
Document Template, these files are templates for Microsoft Word.
.EIF files
See .AIF files.
.EPS files
Encapsulated Postscript File, these are vector graphics. Most drawing programs such as Macromedia Freehand and Adobe Illustrator use this format.
.EXE files
These are executable files, or applications. Most programs end with this extension. It is also used for self-extracting archives, which are programs that when run explode into several smaller programs.
.FON files
These are Microsoft Windows bitmapped screen fonts, used by the Adobe Font Foundry program. Get more information at HTTP://WWW.ADOBE.COM.
.GIF files
Graphics Interchange Format, this is a type of graphic image very common on online services and the Internet. Originated in Compuserve's online service.
.HQX files
These are Macintosh files that have been converted from ASCII to binary (or vice versa) with the BinHex encoding process. See Apple.
.HTM files or .HTML files
When you save a web page to your hard drive or floppy disk, it is given the file extension .htm or .html; this is a derivative language of SGML. There are many different versions and not all browsers execute them the same. The acronym is from HyperText Markup Language.
.IEF files
The file extension for Internet Exchange File.
.INI files
Initialization file, these files are used by programs to set parameters and preferences. Normally, these files should not be changed except by an experienced user. Pronounced eye'n'eye. This is a common source of trouble for Windows users.
.JPG files
Joint Photographers Experts Group, a graphics format designed to take up as little space as possible while retaining as much quality as possible. JPG's are smaller than .GIF's, but take longer to display as they are technically more advanced in content.
.ME files
This is a commonly used extension in DOS programs that tells you to do something. For example, you'll see files named READ.ME or TYPE.ME and that's exactly what you should do with them. If you ever see a file named DESTROY.ME, be very careful! There are some sick minds in this world.
.MID files
Musical Instrument Digital Interface, MIDI files are songs for most sound cards and MIDI equipment. There are different types, and not every .MID file will play on every sound card/midi board. There has been some standardization of audio but great liberties have been taken in some cases with cards that are "Sound Blaster compatible". Some look the same in DOS but not Windows or Windows 95 while the reverse is true on others. Creative Labs was a pioneer in this area; see them at HTTP://WWW.CREATIVE.COM. See audio.
.MIM files
MIME file. MIME is an acronym for Multipurpose Internet Mail Extensions. In other words, .mim files are a way of sending files across the internet as an attachment to E-Mail messages. MIME is simply a format which E-Mail can understand and send. Usually, a file which arrives as a single .mim file, when opened, contains several individual separate files, usually compressed in a similar manner to a .zip file. WinZip, CoffeeCup Free Zip or similar programs can open these files. With the advent of modern E-Mail clients, it is not a popular method any longer and is often the source of virus deposits now.
.MOD files
Music Modules, these are Amiga files that have been adopted by the PC community. They are music files that include the instruments as well as the score, and play through a sound card, not MIDI. You will need a special program to play these files. See audio.
.MOV files
An Apple Quicktime movie file. A .MOV files can be played on the Macintosh or Windows PC. Most current multimedia applications can play .MOV files. See Apple.
.MOZ files
The file name extension for Mozilla or Netscape's cache operations. See Netscape.
.MP3 files
Is the file extension for MPEG, audio layer 3. Layer 3 is one of three coding schemes (layer 1, layer 2 and layer 3) for the compression of audio signals. Layer 3 uses perceptual audio coding and psychoacoustic compression to remove all superfluous information (more specifically, the redundant and irrelevant parts of a sound signal. The stuff the human ear doesn't hear anyway). It also adds a MDCT (Modified Discrete Cosine Transform) that implements a filter bank, increasing the frequency resolution 18 times higher than that of layer 2. The result in real terms is layer 3 shrinks the original sound data from a CD (with a bitrate of 1411.2 kilobits per one second of stereo music) by a factor of 12 (down to 112-128kbps) without sacrificing sound quality. Bitrate, as used in this situation, denotes the average number of bits that one second of audio data will consume.
Because it has been so widely used, when people think of digital audio, they tend to think of MP3, even though it is no longer the standard as of 2005. IPOD (or iPOD, or iPod) uses AAC as a default format and that has become the standard. For that reason, digital song files are often generically referred to as MP3s, and digital music players, including the IPOD, are often referred to as MP3 players. However, iTunes Music Store uses a protected AAC format, while the default for ripping CDs in iTunes is set to AAC. You can, however, change the CD ripping format to MP3, which IS compatible with iPods.
Because MP3 files are small, they can easily be transferred across the Internet. Cell phone users are a great consumer of MP3 technology. (See our list of cellular music providers and our cell ringtone vendors or free locations.) Controversy arises when copyrighted songs are sold and distributed legally or illegally off of Web sites. On the other hand, musicians may be able to use this technology to distribute their own songs from their own Web sites to their listeners, thus eliminating the need for record companies. Costs to the consumer would decrease, and profits for the musicians would increase. See MPG (MPEG) and see audio.
.MPG files
Motion Pictures Expert Group. A format for the digitization and compression of video images created by the Motion Picture Experts Group. See MP3 and see audio.
.PCX files
These are older graphics files, commonly used for clip art. Most graphics programs will import them but they are not handled the same by all programs.
.PDD files
These are files produced and read by Adobe's PhotoDeluxe in one version or another. For all practical purposes, this is a proprietary format but the software will use other more conventional formats. You can get a demo version at HTTP://WWW.ADOBE.COM.
.PDF files
These are files produced and read by Adobe's Acrobat in one version or another. For all practical purposes, this is a proprietary format but the generally accepted standard for preformatted documents on the Internet. You can get an Acrobat demo version, as well as the Adobe Reader (for free) at HTTP://WWW.ADOBE.COM.
.PFA files
These are files produced and read by Adobe's Font Foundry program in one version or another. Specifically, it is PostScript outline font and data. Get more information at HTTP://WWW.ADOBE.COM.
.PFB files
These are files produced and read by Adobe's Font Foundry program in one version or another. Specifically, it is PostScript outline font and data. Get more information at HTTP://WWW.ADOBE.COM.
.PFM files
These are Microsoft Windows font metrics read by Adobe's Font Foundry program in one version or another. Specifically, it is PostScript installer data. Get more information at HTTP://WWW.ADOBE.COM.
.S3M files
S3M files are music files similar to .MOD files except they support up to 16 tracks. You will need special software to play .S3M files. See audio.
.SCR files
These are Windows Screen Savers. To use them, copy the .SCR file into the Windows directory, and run the Control Panel and then the Desktop applet.
.SEA files
Self Extracting Archive, these are Macintosh files that automatically decompress when double-clicked. They can not be used by PC owners. See Apple.
.SFL files
These are PCL bitmapped landscape printer fonts, available in both Portrait or Landscape orientations. They are used by the Adobe Font Foundry. Get more information at HTTP://WWW.ADOBE.COM.
.SFP files
These are PCL bitmapped portrait printer fonts, available in both Portrait or Landscape orientations. They are used by the Adobe Font Foundry. Get more information at HTTP://WWW.ADOBE.COM.
.SIT files
Stuffit files, these are Macintosh compressed files that can be extracted by most Macintosh ISP software or PC users with programs such as UNSIT and UNSTUFF. Many of the files with this extension will not run on PC's even after extraction. See Apple.
.SND files
The abbreviation for sound; these are Macintosh System 7 (and up) sounds that can be played on PC's using converters such as SOX. See Apple.
.SYS files
System file, these are drivers used by DOS and Windows. Be sure to read the file description and any accompanying documents carefully. They are required in Windows 3.x but have more or less been replaced by registry files in Windows 95.
.TIF files
Tagged Image File Format, these are bit mapped graphic images popular among desktop publishers. There are many variations to this typical scanner interface file, though they do not all support the same ability to be resized.
.TMP files
These are system created files that are temporary in Windows operation. They are deleted NORMALLY when the system terminates properly. It is a good idea to purge them regularly by using the disk cleanup option of the drive properties window.
.TTF files
True Type Font, these are scalable fonts commonly used in Windows. You will need to run the fonts control panel to install them.
.TXT files
Text files; these are usually just plain ASCII text that can be read by most text based programs, especially NotePad, WordPad and all other text or HTML editors including word processing programs. These files sometimes have an alternative extension, .ASC, indicating as ASCII file. You can see the ASCII codes and what they do.
.UUE files
A UUEncoded file. UUEncoding is a method of converting binary files to text for transfer across the Internet. Most ISPs' Newsgroup applications automatically convert these files from text to binary.
.VBP files
A file extension for Visual Basic Project. See Visual Basic.
.WAF files
This is the AOL (and Compuserve) for Macintosh Cache file extension. This file is meant to be regularly trashed. It is the equivalent of .tmp (.TMP) files on various Windows computers.
.WAV files
Wave files, these are Windows sound files. If you don't have a sound card, the public domain file SPEAK.EXE may allow you to hear them. See audio.
.WKS (WK1, WK3) files
Worksheet files, these are Lotus 1-2-3 spreadsheet files. Most popular spreadsheet programs can display these files.
.WMF files
See Windows Metafile Format files.
.WP5 files
WordPerfect 5.x file, these files can be read by WordPerfect and many other popular word processing programs.
.WPD files
WordPerfect 6.X and up Windows document files. This is a commonly supported file type for many word processing programs.
.XLS files
Excel spreadsheet file, these are spreadsheet files that can be read by Microsoft Excel and some other popular current generation spreadsheet programs.
.ZIP files
PKware zip archive, this is the most common format for compressed files. See PKZip.
:)
This is an Emoticon, the online means of facial expressions and gestures. Tip your head to the left and you will see the two eyes and smiling mouth. Use them where applicable in chats and E-Mail. Other emoticons are: :D joyous smiley >:( angry smiley }:> devilish smiley :* kissing smiley. On the Internet, this is the equivalent of shorthand.
:)
A smiley (turn your head to the left). An example of online shorthand used in chat rooms, E-Mail, and instant messages.
This is what is used when the person writing is grinning at something. Other versions are the bigger grin: , and the biggest grin: .These are commonly used in chat rooms.
{{{hug}}}
{{{hug}}} is the common online shorthand for giving another Member a hug. Typically the recipient's screen name is placed between the curly brackets; the bigger the hug, the more brackets placed around the name.
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