Final answer:
The old-style diode that uses cat whisker wire is called a Crystal detector, a semiconductor device used in early wireless technology.
Step-by-step explanation:
The old-style of diode that uses a cat whisker wire is a Crystal detector. This device was used in the early days of wireless technology and consists of a piece of crystalline mineral, such as galena, to which a sharp fine wire (cat whisker) is gently touched. The point where the wire contacts the crystal forms a semiconductor junction, which allows current to flow in only one direction, functioning as a diode.