re: 1970's HP Smartwatch Prototype...

my friend had this watch in 1980. it actually played a 'game'



numbers would march from right to left and you would have to use the 'up and down' buttons to switch between 0-9 and hit 'enter' once for each number you wanted to eliminate.

you lost if they got all the way across the screen and it sped up rapidly.

i remember we had it going for like 45 minutes in school one day (no pause back then) and were trying to do math work and kept passing it back quickly under the desks if we had cleared all numbers since you had 3-4 seconds to get back on it.