IBM 847651U Handbook - Page 341

wired so that each signal wire is terminated at the same pin position at each end of the cable. A straight-through cable is used to connect the 10BASE-T port on an Ethernet controller to a 10BASE-T port on a repeater that performs the crossover function. subsystem. In computers, a secondary or subordinate system, usually capable of operating independently of a controlling system, and usually having a single purpose, such as displaying video or reading from and writing to hard disks. A subsystem can be integrated into the system board or on an adapter. SVGA. Super video graphics array. symmetric multiprocessing. In personal-computer systems, a multiprocessing design that enables two or more microprocessors to run concurrently and work independently, with each microprocessor capable of performing any task. synchronous transmission. (1) Data transmission in which the time of occurrence of each signal representing a bit is related to a fixed time base. (I) (2) In data communication, a method of transmission in which the sending and receiving of characters are controlled by timing signals. Contrast with asynchronous transmission. Note: The sending and receiving devices are operated at substantially the same frequency and are kept in an appropriate phase relationship. system board. In a system unit, the main circuit board that supports a variety of basic system devices, such as a keyboard or a mouse, and provides other basic system functions. system unit. In personal-computer systems, the part of the computer that contains the processor circuitry, read-only memory (ROM), random access memory (RAM), and the I/O channel. T telephone twisted pair. One or more twisted pairs of copper wire in the unshielded voice-grade cable commonly used to connect a telephone to its wall jack. Also referred to as unshielded twisted pair (UTP). transceiver. A physical device that connects a host interface to a local area network, such as Ethernet. Ethernet transceivers contain electronics that apply signals to the cable and sense collisions. Transmission Control Protocol (TCP). A communications protocol used in Internet and in any network that follows the U.S. Department of Defense standards for inter-network protocol. TCP provides a reliable host-to-host protocol between hosts in packet-switched communications networks and in interconnected systems of such networks. It Glossary 307