Abstract. We introduce a generalised notion of a real-time speci cation language (\GPLC-Automata") that can be translated directly into real-time programs. In order to describe the behaviour of several GPLCAutomata implemented on one machine we introduce composition operators which form a process algebra. We give several algebraic laws and prove that each system is equivalent to a system in a certain normal form. Moreover, we demonstrate how a real-time speci cation in terms of GPLC-Automata can be decomposed into an untimed part and a timed part.