There has been an argument raging for years over whether you should design circuit boards with 45-degree corners or 90-degree corners. Why make them with corners at all? This breathtaking circuit board art is from a digital watch circa 1975.

The Pulsar Calculator Watch was the first of its kind and came along with a stylus to operate the miniscule buttons. The circuit board traces would have been laid out by hand, explaining the gentle curves rather than straight lines. The chip-on-board construction is wild, with the silicon die bonded directly to those traces on multiple chips in this image. There is also a mercury tilt sensor on this model that would have switched the display off when not being held up to view the time (or calculate your tip at the Ritz).

We found working models of this watch for sale online for about $225-350. That’s a steal considering the original list price for these is reported to be $550 ($2600 considering inflation).

The beauty of the PCB artwork is hidden away, not just inside the watch case, but obscured by the plastic battery housing to which those tabs on the right are soldered. Think of how many geeks were lucky enough to have one of these and never realized the beauty within. If you’re looking to unlock more of these hidden masterpieces, check out [Greg Charvat’s] article on collecting and restoring digital wristwatches.

[via Evil Mad Scientist Laboratories link dump]