It's control system was a small red box in the Drive Room, with two buttons, "start" and "stop". The Holly Hop Drive was designed to get Holly's crew (Lister, Rimmer and the Cat) back to Earth "in seconds". Rimmer believed the device to be pathetic, where Lister was more willing to give it a go.
When transported to this Universe, it becomes apparent that the dominant gender is female. This Universe is completely opposite to the main Universe. Nellie Armstrong was the first human to land on the moon, where Wilma Shakespeare wrote classics such as "Rachel III", implying the British monarchs were opposite gender.
When arriving in this universe, they were greeted by Hilly, Holly's female opposite. The Cat could not wait to meet his female counterpart only to discover his counterpart is male and evolved from a dog just as he evolved from a cat. Arnold Rimmer runs away from his female counterpart as she was attracted to him and he had no interest in her given that her views on men are the same unenlightened ideas he has about women. Dave Lister meets his female counterpart Deb Lister and they get into a drinking contest and eventually get so drunk they wake up in the same bed. But to Dave's surprise the female Rimmer says she hopes Dave gets pregnant. Dave is confused, and Deb tells him that it is the males in their universe that have children and not the females. Arnold Rimmer takes great delight in this news and taunts Lister "you may very well be up the duff laddie! I might even become an Uncle!".
In Backwards, Holly takes on the face of Hilly, showing how madly in love he was with her.
The Holly Hop Drive is also mentioned in "Back To Earth, though noted as "back on Red Dwarf", which means throughout their nine year journey after Series VIII they must have used it or it is still an available device on the ship.