The turntable that could play both sides of a record without turning it over.
The turntable you buy today is essentially the same kind of thing you’d have bought in the 1950s. You have a platter, a tonearm and a cartridge. You drop the needle on the record, let the side of the record play out. then get up and physically turn over the record and repeat.
You’d think that someone might have come up with a way of playing both sides of an LP without any human intervention. As reader Ian points out, someone did try. Behold the Sharp RP-117, which was released sometime in the 1980s.