High-level Data Link Control
(HDLC) A general-purpose data link control protocol defined by ISO for use on both point-to-point and multipoint (multidrop) data links. It supports full-duplex, transparent-mode operation. It is used extensively in both multipoint and computer networks.Some manufacturers and other standards bodies still use their own acronyms, e.g. IBM's SDLC (Synchronous Data Link Control), the forerunner of HDLC and ANSI's ADCCP (Advanced Data Communications Control Procedure). [Fred Halsall, "Data Communications, Computer Networks and Open Systems" 4th edition, 1996, p.237, Addison-Wesley Publishing Co. Reading, Mass., USA].
Last updated: 1997-11-09
high-level language(HLL) A programming language which provides some level of abstraction above assembly language. These normally use statements consisting of English-like keywords such as "FOR", "PRINT" or "GOTO", where each statement corresponds to several machine language instructions. It is much easier to program in a high-level language than in assembly language though the efficiency of execution depends on how good the compiler or interpreter is at optimising the program. Rarely, the variants "VHLL" and "MLL" are found. See also languages of choice, generation.
Last updated: 1994-12-07