Lenslok is a

copy protection Copy protection, also known as content protection, copy prevention and copy restriction, describes measures to enforce copyright by preventing the reproduction of software, films, music, and other media. Copy protection is most commonly found o ...

mechanism found in some computer games and other software on the 8-bit Atari computers, Commodore 64,

ZX Spectrum The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer. Referred to during development as the ''ZX81 Colou ...

Sinclair QL The Sinclair QL (for ''Quantum Leap'') is a personal computer launched by Sinclair Research in 1984, as an upper-end counterpart to the ZX Spectrum. The QL was aimed at the serious home user and professional and executive users markets from small ...

, MSX and

Amstrad CPC The Amstrad CPC (short for ''Colour Personal Computer'') is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Si ...

. The first game to use it was '' Elite'' for the ZX Spectrum.

Overview

Lenslok was released in 1985 as a plastic lens in a foldaway frame. The Lenslok device was essentially a row of

prism Prism usually refers to: * Prism (optics), a transparent optical component with flat surfaces that refract light * Prism (geometry), a kind of polyhedron Prism may also refer to: Science and mathematics * Prism (geology), a type of sedimentary ...

s arranged vertically in a plastic holder. Before the game started, a two-letter code was displayed on the screen, but it was corrupted by being split into vertical bands which were then rearranged on screen. By viewing these bands through the Lenslok they were restored to their correct order and the code could be read and entered allowing access to the game. The device was small enough when folded flat to fit next to an audio cassette in a standard case. In order for the Lenslok to work correctly the displayed image has to be the correct size. This meant that before each use the software needed to be calibrated to take account of the size of the display. Users found this setup particularly annoying, at least in part because they found the instructions that were initially shipped unclear. Additionally, the device could not be calibrated at all for very large and very small televisions, and some games shipped with mismatched Lensloks that prevented the code from being correctly descrambled. The Lenslok system was not used in later releases of ''Elite''.

Software

Lenslok was used only on 11 releases: * ''

ACE An ace is a playing card, die or domino with a single pip. In the standard French deck, an ace has a single suit symbol (a heart, diamond, spade, or club) located in the middle of the card, sometimes large and decorated, especially in the c ...

'', released by Cascade Games * '' Elite'', released by

Firebird Firebird and fire bird may refer to: Mythical birds * Phoenix (mythology), sacred firebird found in the mythologies of many cultures * Bennu, Egyptian firebird * Huma bird, Persian firebird * Firebird (Slavic folklore) Bird species ''Various sp ...

* ''The Advanced Music System'', released by Firebird * '' Fighter Pilot'', released by Digital Integration * '' Graphic Adventure Creator'', released by

Incentive Software Incentive Software Ltd. was a British video game developer and publisher founded by Ian Andrew in 1983. Programmers included Sean Ellis, Stephen Northcott and Ian's brother Chris Andrew. Later games were based on the company's Freescape rende ...

* '' Jewels of Darkness'', released by Rainbird * ''

OCP Art Studio OCP Art Studio or Art Studio was a popular bitmap graphics editor released in 1985, created by Oxford Computer Publishing and written by James Hutchby (original ZX Spectrum version). It featured a GUI with windows, icons, pull-down menus, point ...

'', released by Rainbird * '' The Price of Magik'', released by

Level 9 Computing Level 9 was a British developer of computer software, active between 1981 and 1991. Founded by Mike, Nicholas and Pete Austin, the company produced software for the BBC Micro, Nascom, ZX Spectrum, Commodore 64, Oric, Atari, Lynx 48k, RML 380Z, ...

* ''Supercharge'', released by Digital Precision * ''

Tomahawk A tomahawk is a type of single-handed axe used by the many Indigenous peoples and nations of North America. It traditionally resembles a hatchet with a straight shaft. In pre-colonial times the head was made of stone, bone, or antler, and Eur ...

'', released by Digital Integration * ''TT Racer'', released by Digital Integration

References

{{Reflist

External links

Lenslok Instruction Sheet
(PDF file)
Bird Sanctuary - Lenslok
Article containing further details on Lenslok, with photographs.
LensKey
A Lenslok emulator allowing access to emulated versions of the games. Copy protection ZX Spectrum Atari 8-bit family

Overview

Software

See also

References

External links