Posted By Mike Ash on November 28th, 2005

Update #2: PongSaver is now an official Rogue Amoeba freebie! See this post and download the full version from our Freebies page.

Update: As seen in the comments, the original inspiration for this little screensaver came from hardware developed by Burovormkrijgers.nl. We’ve updated the download to include a small Read Me with proper acknowledgement. As well, for those looking for a Windows screensaver, be sure to check out the Buro Vormkrijgers site, where one is available.

A couple of days ago, someone showed me the Pong Clock. Like any self-respecting programmer should, I instantly wanted one of my own. Not having the hardware to make a stand-alone clock, I opted to make a Mac OS X screensaver instead. You can download it here: PongSaver

When the game begins, the score is set to the current time. The left side’s score is the current hour (in 24-hour time), and the right side’s score is the current minute. Then, the right side scores about once a minute to keep up with the real clock. When it gets to 59, the next score makes it wrap around to 00, and the left side will score shortly afterwards to bring the hour forward. At midnight, left’s score wraps around to 00.

If you want to use this to actually tell time, be careful around the top of the hour. Since it’s not possible for both sides to score simultaneously, there will be a period of time where the score is an hour behind or ahead of the real time. It’s also possible for one side to miss the ball by accident, which then forces it to lose a lot more to resync (although if minutes misses only once, it’s smart enough to just wait for the clock to catch up). During this period the time can be off by up to 12 hours if the right side missed.

That’s all there is to it. Just double-click the PongSaver.saver file to install it. Enjoy!