Here’s a really fascinating circuit that implements a combination lock using relays and logic gates ... in a lot of project. The other chips provide XOR, OR, and AND gates respectively.

Namely, [Robert] seeks to create a database of die images of all 5400 and 7400 series logic ... Project 54/74. These chips are the basic building blocks of digital logic – NAND gates, inverters ...

which was focused on fabricating magnetic coils using extrusion printing. This project used the same copper-lined polymer filament as the fully 3D-printable logic gates, and they realized that ...