What’s the weirdest computer you can think of? This one’s weirder. [Dr. Cockroach] figured out a way to create an inverting NOT gate from just one LED and two resistors (one being a photo-resistor).

The circuit was designed to divide the frequency of a TTL compatible square wave signal which can be programmed with the use of three 7490 to perform the required operation. 7430 – an 8-input NAND ...

Who would have thought that a circuit comprising only two 2-input NAND gates could be so complicated (or, should we say, “interesting”)? Up to this point (click here to see my earlier columns), the ...

As you probably know, processors – and most other digital technology – are made up of transistors. The simplest way to think of a transistor is as a controllable switch with three pins. When the gate ...