BAT file (batch file)

Baseband

baseband the range of frequencies needed to convey a signal itself, with- out a higher-frequency carrier. For example, the video signal from a TV camera is a baseband signal. When modulated onto a radio-frequency carrier so that it can share a cable with many other TV signals, it becomes a broadband signal. Likewise, baseband Ethernet carries one packet at a time; broadband Ethernet carries many different packets, or data packets plus other types of signals, on different high-frequency car- riers. See BROADBAND.

BASIC

BASIC (Beginner’s All-purpose Symbolic Instruction Code) a computer language designed by John Kemeny and Thomas Kurtz in 1964 and pop- ularized by Microsoft in the 1970s.

BASIC is good for programming simple calculations quickly, and you do not have to learn much of the language in order to begin using it. Because no declarations are required, programs can be quite short.
Figure 28 shows a simple BASIC program and the results of running it. In the 1970s and 1980s, numerous software vendors, especially Microsoft, added features to BASIC to support STRUCTURED PROGRAM- MING and a wide variety of DATA STRUCTURES. Today, BASIC is one of the most complex programming languages in wide use, incorporating fea- tures from Pascal, FORTRAN, and C. Line numbers are no longer nec- essary. However, BASIC is still easy for beginners to use, and the newest BASIC compilers still accept programs written in Kemeny and Kurtz’s
original language.

Usage note: Since it is an acronym, BASIC is usually written in all capital letters. Newer Microsoft publications, however, write Basic by analogy to Pascal. We spell it that way when referring to newer Microsoft products. See VISUAL BASIC.

10 REM Temperature conversion program

20 PRINT ”Temperature in Fahrenheit”;

30 INPUT F

40 LET C=(F-32)*5/9

50 PRINT F;” F equals ”;

60 PRINT C;” C”

70 END

Temperature in Fahrenheit? 98

98 F equals 36.66667 C

FIGURE 28. BASIC program and its output

BAT file (batch file)

BAT file (batch file) in Windows, a file whose name ends in .BAT and that contains a list of commands. For example, if you store the commands

dir a: dir b: dir c:

on a file called THREEDIR.BAT, then you can type threedir and the three dir commands in the file will all be executed in succession. See also AUTOEXEC.BAT.

Batch Processing

batch processing the noninteractive use of computers. In batch processing, the user gives the computer a “batch” of information, referred to as a job—for example, a program and its input data—and waits for it to be processed as a whole. Batch processing contrasts with interactive pro- cessing, in which the user communicates with the computer by means of a terminal while the program is running. The crucial difference is that with batch processing the user must put all of the data into the computer before seeing any of the results, while with interactive processing the user can decide how to handle each item on the basis of the results obtained with earlier items.