Stock, the Casio W800-H wristwatch ships with dual time modes, multiple alarms ... The hack involves popping open the case of the watch and exposing the back of the main PCB.

A classic Casio watch is back in some new finish options ... the calculator – you'll find dual time, a 1/100th-second stopwatch, an alarm function and more. It also makes use of Casio's bio ...

While we're talking about cult classic watches, the Casio Calculator watch deserves ... the calculator – you'll find dual time, a 1/100th-second stopwatch, an alarm function and more.