While you’re not likely to see this technique used very much today, there’s a lot you can do with a 555, some logic chips, and a handful of diodes. [Fran] is here with a great example of using ...

The four-layer diode was the key to William Shockley's plan to revolutionize AT&T's phone system. It was a great device in theory, but not in practice -- at least not at the time when Shockley ...