Optoelectronic NOR gates and rotating drum memory illuminate logic

Abstract

Optically routed NOR gates using LED and phototransistors have previously been shown by the author to be capable of building all manner of sequential and combinatorial logic gates. Using scissor cut flexible silicone light pipes, logic circuits can be rapidly built and debugged without the use of an oscilloscope or logic probes. An optoelectronic rotating memory has also been developed leveraging a popular "construction toy system" for the structure and mechanism. The capability to build lookup tables and finite state machines greatly expands the possibilities for developing an innovative hands on digital logic education curriculum for middle through high school students.