A "programmable virus" was a type of man-made virus which could to controlled to do a specific task. One such microbe was present on Z Deck of Red Dwarf, and along with the rest of the ship was re-created by the nanobots three million years later.
When Lister and Rimmer were put on Punishment Detail by Captain Hollister for spiking him and the officers with Boing during their basketball match against the Tank guards: this time their penance having to peel a mountain of potatoes, they got Bob the Skutter to retrieve a programmable virus to help them with their mammoth task.
Bob stole it from Z Deck and passed it to Lister as he was marched in the corridor. They programmed the virus to eat the skins of the potatoes and nothing else, but it didn't work properly, also eating through their clothes and hair, leaving them naked and bald.
Marched into the Captain's Office for yet another reprimand, Rimmer shook the Captain's hand, giving him the virus. Now going bald, an enraged captain ordered them to two months in The Hole. ("Pete: I", Series VIII)
- The programmable virus seems very similar to the Chameleonic Microbe encountered later in the series, since it too was programmed to do a specific task - in the case of the latter, eating metal but not glass. The programmable virus proved merely a nuisance compared to he Chameleonic Microbe; the latter being much more dangerous, since the latter ate through Red Dwarf.