IBM 865741Y Handbook - Page 260

M system, from which the user can select an action to be initiated. (T) MAC. Medium access control. math coprocessor. In personal-computer systems, a microprocessor that supplements the operations of the system microprocessor, enabling the computer to perform complex mathematical operations in parallel with other operations. MAU. Medium attachment unit. Mbps. Megabits per second. Mbps. Million bits per second. MBps. Megabytes per second. MDI. Medium Dependent Interface. microprocessor. A processor whose elements have been miniaturized into one or a few integrated circuits. (T) milliwatt (mw). One thousandth of a watt. modem (modulator/demodulator). (1) A functional unit that modulates and demodulates signals. One of the functions of a modem is to enable digital data to be transmitted over analog transmission facilities. (T) (A) (2) A device that converts digital data from a computer to an analog signal that can be transmitted on a telecommunication line, and converts the analog signal received to data for the computer. MDI port. The port that acts as the electrical and mechanical interface between the twisted-pair link segment and the medium attachment unit. MDI-X. A port on a 10BASE-T repeater that performs the crossover function. multicast. (1) Transmission of the same data to a selected group of destinations. (T) (2) See LAN multicast. multicast address. See group address. N memory. Addressable storage space in the computer that is used for temporary storage of instructions and data while a program is running, or for permanent storage of microcode. Contrast with auxiliary storage. menu. A list of options displayed to the user by a data processing nanosecond (ns). One thousand millionth (10−9) of a second. NetBIOS. Network BIOS. An operating system interface for application programs used on IBM personal computers that are attached to the IBM Token-Ring Network. See also BIOS. 242 Netfinity 3500 User's Handbook