Definitely. You could make a small hardwired state machine and decode its various states into the behavior you wanted, for example. It would probably take a doz

Definitely. You could make a small hardwired state machine and decode its various states into the behavior you wanted, for example. It would probably take a dozen or so 7400-series logic chips (depending on how complex the easter-egg behavior is). That kind of small, non-microprogrammed machine is really common, but people don't build them out of discrete logic any more, or probably even design them by hand. They're written in VHDL or something, and synthesized into silicon or a gate array. They're how a programmable controller is implemented (something has to be under the bottom-most layer of microcode), but they're also used for lots of other little peripheral tasks. I'd guess the student in the article will be formally taught about them in another quarter or two.