A copy of a program or data file. As a precaution, you should back up your computer's hard-disk drive on a regular basis. Before making a change to the configuration of yourcomputer, you should back up important start-up files from your operating system.base memorySynonym for conventional memory.batch fileAn ASCII text file containing a list of commands that run in sequence. Instead of typing each command, you need only type the batch file name. The system executes thecommands as if you had typed each one individually. Batch files must have a filename extension of bat.batteryAn internal power source used to operate a portable computer. To operate a portable computer on battery power, insert a charged battery into the main-battery compartmentof the computer.battery operating timeThe amount of time the computer can run on battery power.battery performanceBattery performance features such as charge time, operating time, and life span can vary according to the conditions under which the computer and battery are used.baud rateA measurement of data transmission speed. For example, modems are designed to transmit data at one or more specified baud rate(s) through the COM (serial) port of acomputer.BBSAbbreviation for bulletin board service. A computer system that serves as a central location for accessing data or relaying messages by modem.beep codeA diagnostic message in the form of a pattern of beeps from your computer's speaker. For example, one beep followed by two beeps is beep code 1-2.binaryA base-2 numbering system that uses 0 and 1 to represent information. The computer performs operations based on the ordering and calculation of these numbers.BIOSAcronym for basic input/output system. Your computer's BIOS contains programs stored on a flash memory chip. The BIOS controls the following:l Communications between the microprocessor and devices such as the keyboard and the video adapterl Miscellaneous functions, such as system messagesbitThe smallest unit of information interpreted by your computer.boot routineThe start-up process of a computer that clears all memory, initializes devices, and loads the operating system.bootable disketteA diskette from which you can boot your system. The Microsoft Boot Disk Windows 98 Series diskette is a bootable diskette.bpiAbbreviation for bits per inch.bpsAbbreviation for bits per second.BTUAbbreviation for British thermal unit.