How does a tamagotchi work?

The Tamagotchi is a handheld electronic toy pet. It was created in 1996 by Aki Maita and sold by Bandai. The Tamagotchi is a small and simple egg-shaped computer. Three buttons (A, B, and C) allow the user do things with the pet such as giving it food or playing with it. There are over 36 versions of tamagotchi, including those in 1996. If you press the first button (a) it highlights an option, if you press the second button (b) it selects the option. If you press the third, (c) it escapes from where you are on buttons.