PSI: A symbolic layout system
Rolf-Dieter Fiebrich, Yuh-Zen Liao, George M. Koppelman, Edward L. Adams · IBM Journal of Research and Development · 1984
A symbolic layout tool, PSI, is described for use with IBM circuit technology. Significant features of PSI are used with multiple circuit technologies, adaptation to rapid changes of technology design rules, creation of nested designs, and extensive designer control over the spacing process.