Lenslok
{{Short description|Copy protection mechanism}}
Lenslok is a copy protection mechanism found in some computer games and other software on the Atari 8-bit computers, Commodore 64, ZX Spectrum, Sinclair QL, MSX and Amstrad CPC. It was created by John Frost, an inventor and electronics consultant, and marketed by ASAP Developments, a subsidiary of J Rothschild Holdings.{{cite magazine |title=Lenslok|magazine=Home Computing Weekly|issue=126|publisher=Argus Specialist Publications|date=20 August 1985|page=7|url=https://archive.org/details/home-computing-weekly-129/page/n11|access-date=23 April 2023}} The first game to use it was Elite for the ZX Spectrum.{{cite magazine |title=Lok-ed Out|magazine=Crash|issue=26|publisher=Newsfield|date=27 February 1986|page=9|url=https://spectrumcomputing.co.uk/page.php?issue_id=993&page=9|access-date=24 November 2022}}{{cite magazine |title=Spectrum Elite has novel protection|magazine=Popular Computing Weekly|issue=35|publisher=Sunshine Publications|date=29 August 1985|page=4|url=https://spectrumcomputing.co.uk/page.php?issue_id=2872&page=4|access-date=24 November 2022}}
Overview
Lenslok was released in 1985 as a plastic lens in a foldaway frame. The Lenslok device was essentially a row of prisms 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,{{cite magazine |title=Lenslocked out|magazine=Sinclair User|issue=48|publisher=EMAP|date=18 February 1986|page=16|url=https://spectrumcomputing.co.uk/page.php?issue_id=48&page=16|access-date=24 November 2022}} 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 on the following releases:
- ACE, released by Cascade Games{{cite magazine |title=ACE|magazine=ZX Computing Monthly|issue=|publisher=Argus Specialist Publications|date=September 1986|page=37|url=https://archive.org/details/zxcomputing-magazine-1986-09/page/n37|access-date=23 April 2023}}
- Elite, released by Firebird{{cite web |last1=Whitehead |first1=Dan |title=Banging the DRM • Page 2 |url=https://www.eurogamer.net/articles/banging-the-drm-article?page=2 |website=Eurogamer |publisher=Gamer Network |archive-url=https://web.archive.org/web/20100604024134/https://www.eurogamer.net/articles/banging-the-drm-article?page=2 |archive-date=June 4, 2010 |date=April 15, 2010 |url-status=live}}
- The Advanced Music System, released by Firebird{{cite web |last1=Waugh |first1=Ian |title=The Advanced Music System (SOS Jan 1986) |url=http://www.muzines.co.uk/articles/the-advanced-music-system/1297 |website=Sound On Sound |access-date=23 April 2023 |pages=65–67 |date=January 1986}}
- Fighter Pilot, released by Digital Integration{{cite web |title=Fighter Pilot Atari Inlay Scans |url=http://www.atarimania.com/game-atari-400-800-xl-xe_1957.html |website=Atari Mania |access-date=23 April 2023}}
- Graphic Adventure Creator, released by Incentive Software{{cite magazine |title=Adventures in programming practices|magazine=Your Computer|issue=9|publisher=IPC|date=September 1986|page=36-38|url=https://archive.org/details/Your_Computer_Magazine_Issue_V609/page/36|access-date=23 April 2023}}
- Jewels of Darkness, released by Rainbird{{cite magazine |title=Jewels of Darkness|magazine=Computer Gamer|issue=20|publisher=Argus Specialist Publications|date=November 1986|page=35|url=https://archive.org/details/Computer_Gamer_Issue_20_1986-14_Argus_Press_GB/page/n35|access-date=23 April 2023}}
- Moon Cresta, released by Incentive Software{{cite web |title=Moon Cresta CPC Inlay Scans |url=https://www.cpc-power.com/index.php?page=detail&onglet=notices&num=1457 |website=CPC Power |access-date=23 April 2023}}
- OCP Art Studio, released by Rainbird
- The Price of Magik, released by Level 9 Computing{{cite magazine |title=The Price of Magik|magazine=Computer and Video Games|issue=57|publisher=EMAP|date=July 1986|page=83|url=https://archive.org/details/ComputerAndVideoGamesIssue057Jul86/page/n81|access-date=23 April 2023}}
- Supercharge, released by Digital Precision{{cite magazine |title=QL Column: Supercharge|magazine=ZX Computing Monthly|issue=|publisher=Argus Specialist Publications|date=September 1986|page=66|url=https://archive.org/details/zxcomputing-magazine-1986-09/page/n65|access-date=23 April 2023}}
- Tomahawk, released by Digital Integration
- TT Racer, released by Digital Integration{{cite magazine |title=TT Racer|magazine=Computer Gamer|issue=20|publisher=Argus Specialist Publications|date=November 1986|page=77|url=https://archive.org/details/Computer_Gamer_Issue_20_1986-14_Argus_Press_GB/page/n35|access-date=23 April 2023}}
See also
References
{{Reflist}}
External links
- [https://web.archive.org/web/20120313194410/http://wos.meulie.net/pub/sinclair/hardware-info/Lenslok_InstructionSheet.pdf Lenslok Instruction Sheet] (PDF file)
- [https://web.archive.org/web/20200107191420/http://birdsanctuary.co.uk:80/lenslok/ Bird Sanctuary - Lenslok] Article containing further details on Lenslok, with photographs.
- [http://simonowen.com/spectrum/lenskey/ LensKey] A Lenslok emulator allowing access to emulated versions of the games.