1985 · Optical Copy Protection Device · Work 991 of 1,871
The living room of a terraced house in England on a winter evening, a small portable colour television on a wooden tea trolley, its curved glass screen glowing with blurred soft bands of red, green and blue, in front of it a hand in a red knitted jumper sleeve holding a narrow flat holder of black grained plastic bent into a shallow C at two hinges, in its middle field a rectangular window of upright crystal-clear prism strips breaking the light into silver glints, its two end fields plain smooth black, on the carpet below a flat black home computer and a small cassette recorder, a standard lamp glowing warm.
What it was used for
Copy protection for home computer games, 1985, invented by John Frost and marketed by ASAP Developments. After loading, the program displayed a scrambled character image. The buyer held the flat plastic piece against the screen, used the keyboard to size a line to its width, folded it into a C and read 2 letters through the prisms; a second code then appeared to be typed in, and the game started. The Centre for Computing History lists 10 titles that used it, among them Elite from Firebird, Tomahawk, TT Racer and Fighter Pilot from Digital Integration, and the OCP Art Studio.
What was new
The idea was to put the key into an optical part rather than a manual: without the original device a pirated copy was meant to be unplayable, and each of the 10 titles listed by the Centre for Computing History needed a uniquely coded one. That is exactly where it failed, and it failed on the paying customer. The Centre for Computing History calls the alignment over-sensitive — a slightly off calibration could reject the attempt and in some cases clear the computer's memory — the letters hard or impossible to read on small portable televisions, the plastic prone to breaking, and production and packaging expensive. An Elite Lenslok was no use with any other game.
What the sources leave open: Guinness World Records states 11 games used Lenslok; the Centre for Computing History lists 10 titles, without saying the list is complete. Guinness dates the first use, on Elite, to 1984, while the Centre for Computing History files the device under 1985. No patent document or unit figures could be found.