1.NUMBERS-Barron's 8th DCIT

3Com

a leading producer of networking hardware, mainly focusing on residential and small to medium businesses. In recent years the compnay has sharpened its focus in this area by acquiring US Robotics but selling off Palm (see PALM PILOT).Their web address is www,3com.com.

3D

see THREE-DIMENSIONAL GRAPHICS

4x,8x,16x…64x (etc)

describing a CD or DVD drive, able to transfer data at 4,8,16, (etc) times the speed of normal audio or video. For example, a 16x CD-R drive can record a full CD equivalent yo about an hour of audio , in about four minutes.

7-layer model

see DATA COMMUNICATION

8.3 filename

…a file name consisting of up to 8 letters or digits, a dot (period), and up to three more letters or digits, as in MS-DOS and Windows 3.-ONTRAST LONG FILENAME

10/100

(describing a network adapter) capable of operating at 10 or 100 megabits per second. See 10BASE-T; 100BASE-T.

10/100/1000

(describing a network adapter) capable of operating at 10, 100, and 1000 megabits per second. See 10BASE-T; 100BASE-T; 1000BASE-T.

10base-2

thinwire Ethernet; a type of Ethernet connection using thin coax ial cable with BNC T-connectors, a bus topology, and a maximum data rate of 10 megabits per second. Cable segments can range from 2 feet (0.6 m) to 607 feet (185 m) in length. See ETHERNET; THINWIRE. Usage note: In this and similar terms, 10 stands for the data rate in megabits per second; base means baseband (not modulated on a higher frequency carrier); and 2 is the approximate maximum cable length in hundreds of meters. The hyphen is often left out.

10base-5

thickwire Ethernet; a type of Ethernet connection using thick coaxial cable with special cable-piercing taps, a bus topology, and a maximum data rate of 10 megabits per second. Cable segments can range from 8.2 feet (2.5 m) to 1640 feet (500 m) in length. See ETHER NET; THICKWIRE.

10base-F

fiber-optic Ethernet; a type of Ethernet connection using fiber optic cable and a maximum data rate of 10 megabits per second. Cables can be as long as 1.2 miles (2 km). See ETHERNET; FIBER OPTICS.

10base-T

twisted-pair Ethernet using Category 3 or Category 5 cable and RJ-45 modular connectors, a star topology with hubs, and a maximum data rate of 10 megabits per second. Each cable can be up to 328 feet (100 m) long. However, because they are unshielded, these cables are somewhat subject to electrical noise if placed close to motors or fluo rescent lights. See ETHERNET; CROSSOVER CABLE; CATEGORY 5 CABLE.

16-bit program

a program that runs on Intel microprocessors using only the features of the 8088 or 80286, with 16-bit internal registers. Most DOS applications and many earlier Windows applications are 16-bit pro grams. Contrast 32-BIT PROGRAM.

24-bit graphics

graphical images that use 24 bits to represent each color, so that each color is made by mixing red, green, and blue, each of which is measured on a scale of 0 to 255, and a total of 16,777,216 colors is available. Often called “millions of colors.”

24 × 7 (or 24/7, 24-7)

available 24 hours a day, 7 days a week.

32-bit program

a program that uses the 32-bit internal registers and large memory capacity of the Intel 386, 486, Pentium, or other compatible micro processor; generally faster than a 16-bit program doing the same computa tion on the same CPU. Contrast 16-BIT PROGRAM. See also WIN32S.

32-bit Windows

Microsoft Windows 95, NT, and their successors for the Pentium and related processors, as distinct from Windows 1.0–3.1 (apart from 32-bit add-ons) or Windows CE. See WINDOWS.

35-mm equivalent

t the focal length of lens, on a 35-mm film camera, that would cover the same field of view as a particular digital camera and lens. See CROP FACTOR; FOCAL LENGTH; ZOOM.

47 USC 227

the 1991 U.S. law that banned “junk faxing” (unsolicited advertising by fax). See JUNK FAX.

100base-F

fast fiber-optic Ethernet, like 10base-F but with a maximum data rate of 100 megabits per second.

100base-T

fast twisted-pair Ethernet using Category 5 cable and RJ-45 modular connectors; like 10base-T but with a maximum data rate of 100 megabits per second. Many network cards and hubs are compatible with both 10base-T and 100base-T transmission. Thus, you can convert a 10base-T network to 100base-T component-by-component and switch to the higher speed when all the components have been modernized.

386

the first Intel microprocessor with 32-bit internal registers and good support for multitasking and extended memory; able to run Windows 95, but too slow for most present-day software. See MICROPROCESSOR.

403 FORBIDDEN HTTP

error message indicating that the HTTP server is not permitted to read a file. This usually means that the owner of the web page has not set the correct permissions on the file. See PERMISSION.

404 NOT FOUND HTTP

error message indicating that a web address is invalid. See DEAD LINK.

419 scam, 4-1-9 scam

a form of fraud conducted through e-mail, usually from Nigeria, where it violates section 4-1-9 of the criminal code, hence the name. The perpetrator sends out mass e-mail claiming to be a bank officer or government official who needs help sneaking some money out of the country and wants to use someone else’s bank account. In return, the vic tim will get thousands or millions of dollars. What actually happens is that the victim’s bank account is emptied, or the victim’s information is used for further fraud. Some victims have even been lured into traveling overseas without proper visas so that they could be trapped and blackmailed. The 419 scam is so common that many active Internet users receive more than one solicitation per day. Newer versions of the scam no longer mention Nigeria, and many of them claim to offer lottery winnings, inheritances, or business deals. See also SPAM; COMPUTER ETHICS.

486

an Intel microprocessor similar to the 386 but faster; predecessor of the Pentium. See MICROPROCESSOR

802.11

(more fully, IEEE 802.11) a set of specifications for wireless net working that give performance similar to 10base-T or 100base-T and implement Wi-Fi product compatibility standards (Table 1). Note that the three 2.4-GHz specifications are downward compatible; that is, a Wireless-B computer will work in a Wireless-G or Wireless-N network. Of course, in that case, communication takes place at the lower speed of Wireless-B.

802.16

see WIMAX.

1394, 1394a, 1394b

see FIREWIRE.

2000

see YEAR 2000 PROBLEM.

2600

a number used as an identifying code by groups of people who exchange detailed information about how to break into computers, tam per with telephone systems, duplicate credit cards, and the like, whether for the purpose of preventing or encouraging these acts. There is a mag azine (2600: The Hacker Quarterly), a newsgroup (alt.2600), and a variety of loosely organized local “2600” groups. See HACKER (definition 3); CRACKER; PHREAK. The number 2600 is from the 2600-Hz control tone formerly used in telephone systems. The Atari 2600 video game machine is completely unrelated.

8088

the Intel microprocessor used in the original IBM PC (1981). It has 16-bit registers and an 8-bit external bus. See MICROPROCESSOR.

68000

the series of Motorola microprocessors originally used in the Apple Macintosh. See MICROPROCESSOR.

80286

the Intel microprocessor used in the IBM PC AT (1984). It is faster than the 8088 and supports extended memory but does not have 32-bit registers or the built-in ability to emulate multiple 8088s; for that reason, multitasking operating systems did not become common until the 386 was introduced. See MICROPROCESSOR.

80386, 80486

unofficial names for the Intel 386 and 486 microprocessors. See 386, 486, and references there.