Back in 2005, a company called Sander Mulder built and sold an LCD clock that displayed the time as an automated game of PONG. The left player's score showed the hours, and the right player's score showed the minutes. The ball was batted back and forth by two paddles constantly (just like the actual game...only without players), and the appropriate "player" missed the ball when the time on its side needed to increment. Then, the ball was served again and the "game" continued. It was incredibly cool.
The 400 that they built sold out in a single day. I kept checking their site
hoping they'd build more, but they never did. As I understand it, there might have been some copyright issues involved...but, at any rate, they never produced any beyond the initial 200. I kept an eye on e-Bay and other online sites hoping that one of the 200 would show up but, on the rare occasion that they did, they sold for thousands of dollars. Way beyond my budget.
Then, on one of my PONG clock searches, I came across a different Pong clock called the Monochron--one that was available as a do-it-yourself kit. At the time, I didn't have enough confidence in my soldering skills to attempt a project of this sort, but I kept eyeing it up every few weeks nevertheless.
Then, I got up the courage to re-cap the monitor in my NBA Jam machine, and it actually went well! Bolstered by my new confidence, immediately ordered the kit. And, after about four hours of soldering, I had a Pong clock of my very own! It's actually an open-source, hackable clock. The ROM is pre-programmed with the Pong display (which works just like the Sander Mulder clock), but you can hack it and reprogram it for other displays should you want. I did't...it was already doing exactly what I wanted it to do.
There's really not a lot to tell on this one. If you want to see what's involved in building the clock, there are excellent step-by-step instructions (with lots of pictures) linked on the Monochron page. There are several sites that sell the kit, but I bought mine from AC Gears for $79.99. (They're gone now...but the kit is still available here.) The soldering is a little tricky at times (some of the components are pretty small), but I was able to complete it with only a couple of mistakes--and I was able to find and correct the bad solder points without any problem. You also have to own (and know how to use) a multi-meter. For me, the hardest part was assembling the enclosure. It would probably help a lot to have a second person hold it together while you tighten the screws. I managed to muddle through it alone, though.
One final note--this is not a wall clock like the Sander Mulder clock. There's no clear sense of scale in any of the pictures I've seen. The finished product is about the size of a bedside alarm clock, and the screen is a little smaller than an iPhone 4 screen. Still...it's a pretty cool toy, and it goes well with my arcade decor.