Two of the earliest British text adventures ever sold, Catacombs and Goblin Towers, both written by Brian Cotton and published by Supersoft in 1981, have been recovered in their original Commodore PET/CBM form. The 45-year-old disks were read on a Commodore 4040 disk drive and copied to a SD card. But Cotton had built a surprisingly clever protection scheme into the game, not to stop copying, but to stop players from listing the BASIC program and cheating their way through the adventure. It had to be understood and removed before the game could be examined and preserved properly.