"There are some individuals whose actions mark them as unfit to live within a civilised society. Your crimes have been of a horrifyingly barbaric nature and throughout this trial you have failed to exhibit even the slightest vestige of remorse. Although it gives us no pleasure to pass such a sentence, we must act to protect the innocent. We decree that your presence within this society can no longer be tolerated."

You are Mike Finn, a space hero sent to the surface of the planet Phoebus after receiving distress calls from another mission. Upon arrival, Triax (a deranged scientist exiled due to his crimes against humanity) steals the destinator from the ship, leaving you stranded along with any possible survivors. Within moments of exploring the land, you encounter a green bird, harmless but irritating as it dives into you repeatedly. Discovering a grenade, you take it, storing it for future use. A harsh particle wind to the east prevents you from moving so back you go and downwards into the next passage. Once there, a turret gun fires, following your movement and you dive down to safety. A closed door waits, so dropping the grenade, you move away as the explosion destroys the metal structure. More passages and caverns are begging to be explored. Welcome to Exile.

One Giant Step For Mike Finn

Peter Irvin and Jeremy Smith met at school and became friends, both owning a BBC Micro. Of the two, Smith was the first to get a game commercially published. Space Pirates and would later release the classic inertia space title Thrust for the format, with Irvin becoming known for his eight way shoot-'em-up Starship Command. Smith went to Imperial College while Irvin attended Cambridge University and it was after finishing their respective courses there that the duo decided to team up and create a game. "I started a sideways scrolling game which had a wizard exploring a cave - which looked great - but with all the things I had intended to put in, it ran out of memory and I realised I had to device a much more efficient way to create and populate the game world. The basis for Exile as a man flying around a 2D environment with guns and physics started with that, though of course Jeremy was also playing with similar concepts for his "Gravitar" game. The timing was such that I had to decide what to do after University, and coincidentally Jeremy was thinking the game - we decided to team up to create Exile, so I shelved the Wizard game and adapted the code to do a huge 2D world map. When we started we were just building the technology to see how far we could get with the limited resources available on the BBC micro before gradually defining what the game would be like."

Very early on, the limitations of the BBC Micro made themselves apparent, with Exile having to be programmed around the meagre 32K RAM, a technical achievement that still impresses its co-creator. "It surprises me even now that Exile could exist in such a small RAM footprint. Exile is to a large extent an academic exercise in writing compact code and data structures. The biggest drawback was the version control - there wasn't any then. We had to write down on bits of paper which functions we'd had to alter, and in which of the fifteen or so modules it was in, and then when it came to merging our separate changes it was a long session of careful cut and paste."

There were several elements that, had the power been available, Irvin would have loved to have included. "One thing we wanted to have was smoother terrain (which was done on the later 16-bit versions) and modifiable terrain (e.g. blowing holes in the rock)."

Despite being a space-based game, Exile is a collage of vibrant colours, giving life to a world inhabited by seemingly intelligent creatures. Although other formats would revamp the game's look, there is something magical about the colourful style that remains impressive today. Yet while many games have artists to craft the worlds within, Exile's environment was entirely down to programming.

"Jeremy and I did them all - there was no budget to pay for artists, and the way the graphics were implemented (the size of each graphic defined the collision box, and thus affected various puzzles) meant that it would have been very time consuming to specify what each sprite should be," explains Irvin. "The overall design was limited by the programming, which is kind of the opposite to what happens in games today. The graphics are as reduced and limited as possible so that the RAM use is a minimal."

Exile eas also one of the first BBC Micro games to make use of speech although this was something of an afterthought rather than meticulous planning. "The background speech was implemented late in the development of the game and was really featured due to boredom at that stage in development. It was actually very quick to implement and not too much RAM used. I think it ended up at just two or four possible volume levels to do the speech waveform which was pumped out under interrupt control at a relatively low rate. The quality wasn't that great, of course, but it was an interesting effect beyond the usual beeps from the sound system on the BBC Micro, and you could understand it - if you knew what it said!"

What made Exile stand apart was its physics engine based on real life gravity and inertia. Objects would bounce upon ground contact and collide with others, holding a heavy rock would slow down Finn's speed; wind drafts repel Finn in different directions. Most impressive of all is Finn's movement, floating around in a manner expected of a space environment. Yet this aspect of Exile, turned out to be the easiest to program. "We both had a strong maths education, so the physics wasn't difficult except in balancing all the effects to work together properly (e.g. what coefficients of restitution for different mass objects - i.e. how fast to rebound off other things) and without using up much RAM or being slow" comments Irvin. "This was actually one of the most interesting bits to implement. The physics code was re-written several times to make it faster or to deal with new game features that required it." The remarkable physics engine combined with the intense puzzling of Mike Finn's escapades has yet to be replicated.

While the sheer size of the world is initially overwhelming, the variety of caverns, passages and creatures to encounter meant that exploration was the key to progress. Incredibly difficult, the multitude of puzzles had different solutions, giving the game a non-linear approach and the feeling of liberation that makes Exile such a compelling experience. The inability to die, merely re-spawning at the last teleport spot, added to the illusion of freedom and allowed players to take risks with their puzzle solving. Despite this, few have made it to the end, and even less have rescued all survivors, but those that have can rightfully be proud of the colossal achievement. The inclusion of hidden messages throughout the game such as 'She wants you badly' and 'You have killed Triax' were "partly to keep the hackers amused, and keep people guessing that there were things still to do in the game."

Creatures ranging from monkeys, birds, wasps and robots would hinder progress to various sections, and guns integrated in the scenery fired upon approach. Wasps would swarm, birds follow into the deepest depths of Phoebus, others simply turn away once left alone. The different approaches each species would use gave the impression of thinking ability, not computer generated images. Irvin explains a little of how this was accomplished. "There were a set of powerful high level functions that were available for each object's tactics/strategy code to use - like one that did "move towards the last seen position of the object I'm following by walking on the ground", or "fire my weapon at the nearest enemy type", though it is more sophisticated than this. Each object had "state" to keep track of what it is doing, and this is updated occasionally or according to various events that happen. Subroutines for tactics code were shared by various objects, so for instance a robot motion function would also be used by the crabs. This way memory was saved."

Interestingly, the novella that accompanied the game was conceived as a method to discourage piracy, although its inclusion also added value to the overall package. Written by Mark Cullen in conjunction with the game's authors, the novella added immersion to what was already an atmospheric experience, setting the scene for the game nicely. Sadly, the novella would not see life on the Amiga and Atari ST with the story briefly re-written to keep the premise intact. "We had no control over this decision - I think it would have been better to keep the original story available for people to read if they so wished" remarks Irvin. "However, the BBC Micro audience was probably more cerebral than the later mass market Amiga audience because the BBC Micro was meant to be an educational machine before being a games machine."

The other main copy protection method was in the way the game was programmed. If a copied or cracked version was detected, certain elements would malfunction, making it impossible to complete.

Life On Other Planets

The success of the BBC Micro version meant that conversions to other computer formats were inevitable. Exile would see itself on the Acorn Electron, C64, Amiga, Atari ST and CD32, all offering the same epic world but with some alterations. The Electron version saw Finn's space suit change colour to yellow instead of magenta and Triax is cyan rather than green while other graphical changes were down to the Electron's less powerful hardware.

"We did the conversion for the C64," says Irvin. "We paid for some people to do an initial direct conversion from BBC assembler to 68000 (as we had no experience in this platform) and did the other improvements ourselves from this starting point."

Exile fan William Reeve who had just finished programming Pipeline on the BBC Micro, was responsible for the acclaimed Amiga version and also converted the Atari ST title.

"The graphics were redone by a professional artist (Herman Serrano) supplied by the publisher (Audiogenic)" comments Irvin.

Improving the graphics provided its own memory problems despite the superior technology and is the reason why the A500/600 version was just a straight port with enhanced visuals. The Atari ST version was faster than its Amiga counterpart and slightly better to look at overall. In 1995, the Amiga 1200 would see an AGA release, this time by Tony Cox, offering a revamped look and extra areas. The CD32 edition was based on the Amiga 1200 version, with the graphics 50% zoomed in to fit a console environment which in itself threw up some scrolling problems during programming and limitations of memory. In order to compensate, a high amount of compression was used for the save game file.

Although the multi-format conversions keep all gameplay features intact, it's the BBC Micro version that remains the most popular. "I think the 16-bit versions were better than the 8-bit versions, though they have less of an impact in people's minds on these platforms because the BBC version really did stretch the limits of the machine. Some people that had already played the BC version and then played the Amiga version preferred the BBC version."

To Infinity And Beyond

Jeremy Smith went on to work as a graphics artist for games like Supercars at Magnetic Fields before joining Core Design and producing titles like Wonderdog. Sadly, Jeremy Smith passed away shortly after in 1992, leaving Peter to reminisce about the talented programmer.

"It was good to work with Jeremy on Exile - at that time it would have been too difficult to do such a game without some kind of team support. It was not difficult to split the work between us, and it was great to have someone turn up with a chunk of code that just slots in and suddenly makes a big change."

After Exile, Peter Irvin worked on 3D design for Frontier Elite II on the Amiga and Atari ST before developing Sega 32x title Darxide with Frontier Developments, a shoot-'em-up that was released at the end of the machine's life span. Nowadays, Peter Irvin runs Inventivity (www.inventivity.com) working on titles for mobile devices.

A sequel for Exile was never in the pipeline, leaving Mike Finn resigned to exploring Phoebus for over 15 years, still offering a captivating experience for those who stumble across it. Those interested in seeing the hapless space hero return to Phoebus should keep an eye on Irvin's website for updates.

"Strangely enough, I was recently contracted to implement a version of Exile as a demo for a big mobile phone chipset supplier - for the Broadcom 2702 Game Framework. This was a bizarre experience having to go back to the old game and produce a version of Exile in C (The Amiga AGA version). I hope this actually gets put on the client's customers' phones as Exile works really well on these mobile platforms - the small screen works well, and the gameplay with Exile can be dropped and picked up without problem - which really is a requirement on these devices. I have decided that I might as well do something with the new code and put it on other phone platforms too - like Nokia Series 60, and Microsoft Windows Mobile devices - watch this space!"

Thanks to Peter Irvin for talking to Retro Gamer #30. Credit to Hall of Light (http://hol.abime.net/) for the box scans.