ACM - affordances
Roy Kaplow
Michael Molnar
Proceedings of the 3rd annual conference on Computer graphics and interactive techniques - SIGGRAPH ’76
Computer assistance for writing interactive programs
Processor Handbook, PDP 11/40, Digital Equipment Corporation, Maynard, Mass
Storage Display Unit-Model 611 Data Sheet, Tektronix, Inc
Digivue Model 512-60 Data Sheet, Owens-Illinois, Perrysburg, Ohio