Changes

DJL Software (for "Dave J and John LookerSoftware") is mainly known as the co-author of the [[Speedlock|Speedlock]] protection system.

A fast loader and protection used on many cassette games, and as a protection on disc games released in the UK.

But he DJL was also the author of several Amstrad games including [[3d Stunt Rider]] and [[Nigel Mansell's Grand Prix]], in addition to self-published titles such as [[https://www.retrogames.co.uk/041976/Sinclair/Frogger-by-DJL-Software|Frogger]].