Exile

[Rich Talbot-Watkins]

Matt Godbolt pointed me at this interesting blog post on Exile:
http://scarybeastsecurity.blogspot.co.u ... egant.html

It's great to see that it's still inspiring people... 26 years on

[davidb]

The coronium rock solutions are quite neat, and may be what the original authors intended players to do. Otherwise there doesn't seem to be much point to the piranha-acid-bush complex near the fourth (fifth?) key pass.

I think one of the solutions (edit: this walkthrough, actually) does recommend the blaster trick to get the coronium for the mushroom immunity pill puzzle but that area is just such a pain to traverse that any tricks that can help are appreciated.

The other, unmentioned part of the game that almost certainly does require playing the game engine, rather than the game itself, is where you need to get the first pair of coronium rocks out of the windy tunnel area. In my view, the game relies far too much on coronium rock puzzles, unforgiving dynamics and playing the engine to be fun after a certain point. If the rune door had been easier to break through then I think it would have made it a better gaming experience, even though the game gets much harder after that.

The use of blue mushrooms to get the extra weapon is clever. I wondered if those imps (and others) could be persuaded to hand over items, but never found the right bribe. I wonder if you can get two of those weapons - one from each set of imps. Another interesting thing is that one of the bushes in the upper right area of the map, near where Fluffy is found, eats piranhas. There seems to be no purpose to it - it's just one of those things.

[jms2]

That's really interesting - the blog post also links to a disassembly, which I didn't know was available online.

[davidb]

In the same vein as the description of how to get the extra weapon earlier in the game than usual, there's a trick mentioned in EUG 19 where you can get access to the icer, protection suit and grenades before getting the RCD. However, I couldn't manage to perform it successfully - reminding me that it seemed unfair that the player needed to learn the ability to jump then crawl through narrow horizontal passages in order to progress in parts of the game.

Anyway, there's another approach that can be used to get hold of the icer and other goodies. The attached GIF was made quite some time ago to illustrate this. Throw a couple of wasps and a grenade through the gap below the door and look up to see what the turret will do.

[KarateEd]

That's really interesting - the blog post also links to a disassembly, which I didn't know was available online.

Just in case people wanted to peruse the listing, I've put it into a text file... hope it is enlightening....

Ed......

[BigEd]

Jimmy Maher's comprehensive video game history has just reached the golden age of British open world action adventures, and covers Exile here:

Coming nine years after Warren Robinett created his Adventure on the Atari VCS, Exile, which embraced much the same design philosophy but blew it all up to well-nigh absurdist proportions, feels like the logical end point of what he began. It’s hard to imagine a bigger, more fascinating, more daunting action-adventure than this one. And really, it’s hard to imagine why anyone would even want such a thing. Exile is packed full of so many creatures and puzzles and hidden nooks and crannies that its secrets have yet to be exhaustively cataloged, in spite of the best efforts of a small but devoted cult of fandom who have been at the job for a few decades now. Its warren of underground caverns just go on and on and on, with something new to discover behind its every twist and turn. How remarkable that the game’s programmers, Peter Irvin and Jeremy Smith, created this monster inside the most constrained platform of any of the games we’ve looked at since Robinett’s Adventure: a 32 K BBC Micro.

A footnote on copy protection:

It’s likely that the majority of people who have played Exile have done so on versions that were literally impossible to complete. One other aspect of the game’s legend is its copy protection, which stands as the most devious of its era. Instead of simply booting you out of the game, the layers upon layers of protection, personally devised by Irvin and Smith, subtly alter the game to make it impossible to complete

[davidb]

I'm a bit disappointed that he didn't cover Exile in much detail, though I can understand that it doesn't really fit in with many of the other games that he revisits. It's also a niche title which may have had little impact outside a limited circle of players and developers, not to mention designers.

A lot of the interesting features for many of us are the technical details and quirks of the game, so an interesting article about Exile for us probably wouldn't appeal so much to an audience reading about game design and gaming history in general. Having said that, I would have thought that the "impossible to die" mechanic would be notable for a 1980s game, with the most common failure mode for players in the early part of the game - other than just giving up - being the problem of running out of energy, making it a bit like The Sentinel in that respect.

[DutchAcorn]

About the copy protection; if this story is true, do we know if the STH Exile version is affected?

[Rich Talbot-Watkins]

The story's not true, at least not on the Acorn versions. The worst effect of hacking out the copy protection code (badly) is that it would hang after two minutes, like the demo mode.

[BigEd]

That's good to know. Back in the day, I never heard of Exile. I'm impressed by the scope but I think it might be beyond my dedication to tackle it. Thrust is more my level.

[davidb]

The footnote about copy protection is talking about the ports of the game to other platforms, though I don't know where he gets the idea that the majority of players experienced it on those platforms. From what I've read (from YouTube comments so take with a pinch of salt) the game engine loses track of objects on the various cracked versions of the game and maybe also generates the map incorrectly.

I believe you could achieve similar things with disappearing objects in Acorn versions of Exile by hoarding grenades.

[Rich Talbot-Watkins]

The copy protection on the Beeb version was still pretty nasty. There were two parts to this: the disc protection and the novella password request. The disc protection was pretty unusual: the disc had its own encrypted catalog sector, and implemented custom file operations to load them (by redirecting the standard OS vectors).

But the novella protection was a bit more sneaky. When I found the check in-game for whether the right word had been entered, and removed that code, I remember the game would still crash after a couple of minutes. I can't remember the details, but it was necessary to remove the code very carefully so that everything worked correctly (could it have been checking that the original code was still there? I'm not sure...)

Seems like Irvin and Smith took it to the next level with the C64 version and made it really difficult to know whether it had been successfully stripped or not, by making subtle changes which you wouldn't notice until a long way into the game. We employed the same trick on a PS1 game I was involved in many years back.

[BigEd]

You're quite sure then there are no remaining subtle changes in the cracked game? It's almost a pity, as there might have been more to learn...

[sydney]

...though I don't know where he gets the idea that the majority of players experienced it on those platforms.....

I think the game was quite popular on both the c64 and amiga. A game with poor sales figures on either of those systems still probably outsells a 1988 BBC/electron best seller.

[davidb]

When I played the transferred-to-disk Electron version in the 1990s, I noticed that the fireballs (one in the lower caverns, two in the rune door area) failed to behave properly, but I don't know if that was due to the conversion itself or to ElectrEm. Since they just dropped to the ground and were harmless to touch, it made the game much easier in those sections.

[davidb]

I think the game was quite popular on both the c64 and amiga. A game with poor sales figures on either of those systems still probably outsells a 1988 BBC/electron best seller.

It would be interesting to know the figures. I'm not disputing that they could be higher, but it often seems that Acorn users were a lot more vocal about the merits of the game.

[sydney]

I think it had such an impression on Acorn gamers because it stood out more on Acorns than those other systems. Exile on the beeb is voted number 3, with 12 votes, in my top 100 list as voted for by beeb/electron users here. On the C64 it's number 28, with 72 votes, as shown here and pressing the games button. It doesn't appear in the lemon amiga top 100.
If you were still using an acorn in 1988 then exile blew you away, on the c64 it was just another great game.

[Rich Talbot-Watkins]

You're quite sure then there are no remaining subtle changes in the cracked game? It's almost a pity, as there might have been more to learn...

Can't be 100% sure, though we have an annotated disassembly and can see where the novella protection code used to be (and how it was removed). I would remain fairly confident that the Beeb disc images of Exile going around are intact and can be completed. In fact, there's a series of YouTube videos showing it played to completion on BeebEm, so I guess that's probably good enough proof.

[BigEd]

It does sound good. So long as the game can be completed without using glitches, that's a good sign.

[John_Acorn]

Matt Godbolt pointed me at this interesting blog post on Exile:
http://scarybeastsecurity.blogspot.co.u ... egant.html

It's great to see that it's still inspiring people... 26 years on

Strange the names that appear. I thought William Reeve worked on a non-Acorn port. Also I found somebody called Richard Williams: http://everygamegoing.com/landing/items ... le_V1.html

[Kevin Edwards]

Just thought i'd add a bit more detail about the tape protection for Exile on the BBC Micro.

Just to confirm that there wasn't anything special communicated between the physical protection system and the game when it executed.

The protection was the standard, painful 6522 decoder stuff. I don't recall doing anything special during the loading / decoding to inform the game that things were either OK or BAD.

The game code/data was loaded, de-crypted and then executed in a fairly standard way.

The Novella 'protection' was something separate from the tape protection, something i don't have any knowledge of.

I do like the idea of subtly affecting game-play in such a way as to stop it being playable if the game has been hacked or modified in some way. Nice idea, assuming it doesn't go badly wrong!

Cheers,
Kevin.

[sbadger]

Nice idea, assuming it doesn't go badly wrong!.

I guess this is the main problem with modern DRM; it just ends up p'''ing off your actual customers, It never prevents piracy.

I get so rild with warnings and adverts I cannot skip on dvd/br ... makes my wee boil! because I can almost guarantee pirate versions dont have any of that rubbish.

[Rich Talbot-Watkins]

A good 20 years ago now, I worked on a game on the Playstation called Medievil. Sony had just introduced a library called Libcrypt, which took advantage of the fact that the Playstation hardware could read raw data from CDs, and that all releases were mastered with deliberately incorrect correction bits in certain parts of the disc. So, with Libcrypt, we were able to read values from the disc which would not be preserved in a copy (which would always be written with valid correction bits). This acted as a key, which we then used to generate all the magic values used in one of the levels well into the game. Result was that a copy appeared to function perfectly, until you were halfway into the game, at which point the broken level would start up and be largely unplayable, and certainly not allow the player to progress further.

Sounds like C64 Exile used the same kind of trick. It's not really the same issue as DRM / nagging unskippable adverts - an original works without hassle, it's just that a copy will be subtly broken. I love this, simply for the fact that there'll be no obvious code which is saying "is it a copy? then crash".

By the way, I can't think of a worse thing than playing Exile from tape, particularly the enhanced version. You'd have to be really sure you wanted to save your position and then start the 15 minute long loading process again

I hadn't realised you were still doing Beeb stuff by that time Kevin. I guess the post-Ultimate protection systems were a bit more "diluted", now that you weren't able to assume OS 1.20 any more, nor activate IRQs (given the small differences in interrupt timing between 6502 and 65C12). Did you ever do any disk protection systems, or was there just not the scope to be quite so 'evil'?!

[kieranhj]

A good 20 years ago now, I worked on a game on the Playstation called Medievil. Sony had just introduced a library called Libcrypt, which took advantage of the fact that the Playstation hardware could read raw data from CDs, and that all releases were mastered with deliberately incorrect correction bits in certain parts of the disc. So, with Libcrypt, we were able to read values from the disc which would not be preserved in a copy (which would always be written with valid correction bits). This acted as a key, which we then used to generate all the magic values used in one of the levels well into the game. Result was that a copy appeared to function perfectly, until you were halfway into the game, at which point the broken level would start up and be largely unplayable, and certainly not allow the player to progress further.

Without wanting to go too OT, we did a similar thing with Banjo-Kazooie on the N64. There was a special chip on the cartridge that we could send data to and get back in a known encrypted / signed state. We passed data through it and used this to seed the game in various places. It was all quite subtle so some of the doors wouldn't open or a race would be impossible to beat. The pirate systems at the time, like Doctor 64, required the user to have at least one cartridge with the custom chip plugged in. Unfortunately for us another game, that will remain unnamed, came out shortly afterwards that was produced in vast quantities but ended up in the bargain bin and cheaply available.

At least that's my recollection of events!!

[sbadger]

I wonder if such a subtle and pernicious anti piracy scheme has ever backfired, in that it's damaged the reputation of a title.
If something was widely copied but the game came across as difficult or buggy ,word of mouth for actual prospective buyers would be poor?

[Rich Talbot-Watkins]

When I've heard of this in the past, the original developer has intervened, outing those complaining about the 'bugs' as a pirate.

e.g. Arkham Asylum from here:
http://www.cracked.com/article_19162_6- ... rates.html

[kieranhj]

I wonder if such a subtle and pernicious anti piracy scheme has ever backfired, in that it's damaged the reputation of a title.
If something was widely copied but the game came across as difficult or buggy ,word of mouth for actual prospective buyers would be poor?

Potentially. It is possible to be too clever for one's own good. Although back in the good old days of cartridges they were a lot harder to copy anyway so anyone sophisticated enough to invest in this kind of system kind of knew they were in a copy protection arms race vs Nintendo.

Back on B-K I had an idea to have a copy protection layer if the save game chip wasn't as we knew it would be specified. That was ultimately removed because we couldn't guarantee the long-term reliability of the EEPROM chip (or whatever it was) and there was a possibility that a second production run of the cartridges might use a different IC for cost reasons.

Stop & swop on the other hand.

[Kevin Edwards]

Hi Rich,

Yes, Exile ( tape ) was one of the last BBC Micro games i protected - personally, i'd moved on to other projects and platforms, but did this as a one off. The authors were keen to have their game as secure as possible, but it also had to work on the Master 128, B+ etc. Yes, i did have to dilute the protection to ensure the decoders would work on all hardware variations.

Nightshade has the most complex protection of all the systems i worked on - however, Lunar Jetman also had some of the nastier features from Nightshade. Has anyone looked at that in detail?

I did have some rather nasty disk protection systems that were ready to go but were never used. They defeated Basil Bloom's CopyAll, Disk Duplicator, Vector etc.

However, they couldn't be used for the following reasons:-

1.) Commercial disk duplicators couldn't master the disks due to the complexity of the formatting / data layout - oh the irony! Companies such as Ablex couldn't copy them.

2.) Lots of non-8271 DFS systems were in existence and they had poor OSWORD &7F disk sector reading implementations. These varied from very poor emulation through to almost working - many of them couldn't boot Elite! There were too many 'DDFS' alternatives to support and the more aggressive the protection, the more chance of failure. From a commercial point of view this would have been suicidal as you would get lots of returns which would be costly and bad for consumers.

Exile is certainly one of the best games produced for the Beeb and one of my personal favourites. A technical masterpiece!

Kevin.

[Rich Talbot-Watkins]

Exile disk version had some pretty good protection as well (though, after the initial fairly trivial decrypter, it amounted to just putting some new filing system code in place via the vectors, after which you could simply *LOAD and *SAVE the files onto a clean disk!). I think the trickiness came with duplicating it with the protection intact; if I remember correctly, there were some extremely strange track IDs which couldn't be written with an 8271.

It's a shame none of your disk protection systems got out in the wild Kevin! Am I remembering correctly that one of yours actually required the disc surface to be scratched manually, or some crazy thing like that? It's a shame we never saw some of the tricks that appeared on other platforms (like fuzzy bits which read differently from one time to the next), but as you say, the non-standard disk systems like Opus would've been a problem.

[crj]

Yes, Exile ( tape ) was one of the last BBC Micro games i protected - personally, i'd moved on to other projects and platforms, but did this as a one off. The authors were keen to have their game as secure as possible, but it also had to work on the Master 128, B+ etc. Yes, i did have to dilute the protection to ensure the decoders would work on all hardware variations.

I concur that the protection wasn't as strong as some of your earlier titles. At school, we got around it in a couple of evenings, whereas some of your earlier efforts defeated us entirely without the use of hardware hackery. (Lacking the money for anything snazzy, and permission to do anything too invasive to the school's computers, we simply ran a DIP switch to some of the link headers so we could write-protect the sideways RAM then map it in place of the OS.)

Having circumvented the protection, we hacked it so it could run from NFS and ADFS instead of DFS. And I found a spare dozen bytes for a routine that looped until you'd unplugged the network cable so the next NMI wouldn't crash it. Happy days!