The Apple Watch possibly just got a whole lot more useful. Programmer Nick Lee has brought Mac OS (technically called “System”) 7.5.5, an operating system that dates to the early 90s, to the Apple Watch thanks to Mini vMac and watchOS 2. Watch it running in his YouTube video:

The oldest Mac able to run 7.5.5 is the Macintosh Plus, which came with 1MB of RAM, a SCSI port, and a Motorola 68000 processor running at 8MHz. Upon launch in 1986 it cost $2599. The Apple Watch, on the other hand, comes with a S1 integrated computer with 512MB RAM and a processor of similar power to the one found in the iPad 2.

The big question that comes to mind when watching a video like this is “why?” The best use for an app like this is to show off a bit of history to your friends on your wrist, but it’s kind of difficult to come up with a situation where there would be a genuine need to have this.

With watchOS 2 coming this fall with app support, it’s likely we’ll see even more apps that make us wonder if it’s absolutely necessary to have that on your wrist. But similar to the early days of the iOS app store, developers will experiment with ideas like the above to try and work out what exactly a computer on your wrist is really useful for.