and Atari ST release use a more conventional tiled map to allow greater customisation and variation in the landscape. Circa 2012 the source code of the BBC Micro version was reconstructed through disassembly. Peter Irvin later allowed the non-commercial redistribution of the Amiga version of the game. Releases The game was first published for the Acorn Electron and BBC Micro in 1988 by Superior Software and later ported to the Commodore 64, Atari ST, Amiga and CD32, all published by Audiogenic between 1991 and 1995. The game mechanics and level design are broadly similar across all Exile versions but visuals and sound vary depending on the capabilities of each system. Exile has never been released outside Europe. Acorn Electron / BBC Micro The standard 32 kB BBC Model B version uses a specially defined screen resolution (eight physical colours; 128 pixels across × 128 lines down = 8 kB screen memory), smaller than full screen MODE 2. This is to free up memory for game data – a common technique in complex BBC games. The simplified video hardware found in the Electron does not support this technique, so the additional data remains visible around the screen border. For speed reasons, the Electron release has only four on-screen colours. It did however boast a slightly larger view window of 128 pixels × 192 lines down. Exile offers the option of playing an enhanced version of the game on a BBC Micro upgraded with a 16 kB page of sideways RAM. These enhancements include sampled sound effects and digitised speech ("Welcome to the land of the Exile." and "Alien die!"), as well as a larger visible screen area (eight physical colours; 128 pixels across × 256 lines down = 16 kB screen memory). The extreme measures taken to make the game operate on a standard BBC Micro mean that the main game had no on-screen status indications or text of any kind, or even load and save routines. Fuel and energy levels are sounded out by a series of chimes when a weapon is selected, and pocket contents can only be checked by putting items back into the player's hands to make them visible. Saving the game entails pressing a shutdown key, resetting the computer, and launching the loader programme again. Despite such measures being forced by necessity, they formed part of the character and appeal of the game, leading to innovations