A Crystal Holograph Projector (known as a HOP for short) is a self-powered crystal that can receive and translate signals into a three-dimensional projection. These projections are displayed directly above the HOP crystal, which is usually about the size of an adult male's head and often glows a dull red.

HOPs can be converted into computers (HOPCs) by adding an operating system, software and, most importantly, interactive function through a virtual keyboard display.

Because there is then no need then for a physical keyboard or mouse, HOPCs are fully mobile.