A Pascal compiler is described which can parse a limited subset of Pascal, and generates a circuit description in a format which can then be input to the UK5000 gate array software. A set of Pascal utilities completes this package by allowing the Pascal circuit description to be compiled by a standard Pascal system. This complete package allows the development of systems containing single or multiple UK5000 chips. Moreover this can be performed on any software development system. The use of Pascal as a hardware description language is not new, but this system promotes good top-down hierarchical design of UK5000 chips and also allows quick and efficient verification of the system, prior to the automatic generation of data for entry into the UK5000 system.