Code: The Hidden Language of Computer Hardware and Software, 2nd Edition

Chapter Eighteen

Let’s Build a Clock!

What a fun project it might be to build a clock! Imagine a big old-fashioned grandfather clock, with an intricately carved wood case and a glass door through which you can see the ponderous swinging pendulum. Behind the ornate metal dial is a complex of gears that keep time using a clever little mechanism called an escapement, the ticking and tocking of which reverberates throughout your home and triggers solemn chimes every hour.

But no. That’s not the kind of clock we’ll be building. The clocks in this chapter are instead digital clocks that display the hours, minutes, and seconds with numbers rather than rotating arms on a dial. In fact, the first version of this clock won’t even display conventional ...