Berkeley UNIGRAFIX is a graphics system that runs under the UNIX operating system. It comprises a collection of rendering programs and scene generating programs. Scenes of objects are described in a terse, human-readable format called the UNIGRAFIX descriptive language. In order to display parametric curves and surfaces using UNIGRAFIX, we developed a scene generator called UGTRACE. It traces a set of parametric equations and generates a scene file written in the UNIGRAFIX format. Two tracing modes as well as two displaying modes were designed. The Berkeley UNIGRAFIX system was installed in the McMaster environment. For our purpose, we also modified the various device drivers of UGDISP, the latest version of the renderers. Available output devices include the AED colour graphics terminal, the IMAGEN laser printer and the IBM PC emulating a Tektronix 4010 terminal. UGDISP is used to display scene files generated by UGTRACE. / Thesis / Master of Science (MSc)