This repository contains resources prepared and collected in support of my talk planned for presentation at the Develop Denver conference, August 10th and 11th 2017.

The talk is planned around the use of a purpose-built demonstation unit to quickly configure and demonstrate the circuits to be discussed, as well as for exploration of other circuits at a more leisurely pace.

This repository will contain design files for the demonstration unit and the deck.js-based presentation slides.

As submitted, the talk description is as follows:

Three quarters of the twentieth century elapsed prior to the appearance of microprocessors as we've come to know and love them. During this time, there still existed a need for programmatic automation in applications such as industrial and architectural control and telephone switching systems. The technologies and techniques developed to address these needs would end up directly informing the design of later general-purpose computers.

In this talk, we will physically demonstrate the use of electromechanical hardware available a century ago to create basic logic circuitry. We'll see not only how these circuits underpin modern computer architecture, but also how the design patterns and terminology have remained with us in surprisingly recognizable forms. Finally, we'll come to an appreciation of the problems and solutions facing people during what is called (as we'll see, somewhat mistakenly) the "pre-digital era".

• panel/ contains the design files for the demonstration unit's front panel.

• An excellent treatment of ladder logic, including many of the circuits demonstrated in this talk, can be found at https://www.allaboutcircuits.com/textbook/digital/chpt-6/ladder-diagrams/

• A broad survey of technologies contributory to and the general development of modern computers is presented by the blog Creatures of Thought.