It now appears all but inevitable that Sony will officially announce the Playstation 4 on Wednesday the 20th of February. Apart from rampant speculation about price and release date, the question on many peoples lips is "will it be backwards compatible?". And that is a very good question.
More than any previous generation, people have invested heavily into Sony and Microsoft's current consoles. Part of this is due to the unprecedented length of this console generation - The Xbox 360 will celebrate it's 8th birthday this November - but it is also down to the way we've consumed content on these platforms. We no longer simply have a stack of physical games to represent our investment in a console; In the online age we have accounts, avatars, trophies, achievements, and a hard drive full of downloaded games.
The fact that so many of us have invested so heavily has led many people to believe that backwards compatibility will be a given in the next generation. Unfortunately, this may well not be the case, and in order to find out why we must first go back in time.
The Atari 7800
The first console to feature backwards compatibility was Atari's ill-fated 7800. By including chips from the Atari 2600, gamers were able to play their old copies of Pitfall!
. This is where the first lesson comes in. By far the most popular way of achieving backwards compatibility is to include the old console's processors on the new console's motherboard. This is how the PS2 plays PS1 games and, the DS plays Game Boy Advance Games. The benefit of this system is that - because you're essentially including the old console inside every new one you sell - compatibility with the old console's games is nearly perfect. The downside is that it costs the console manufacturer quite a bit of money for what is, essentially, unnecessary hardware.
Unfortunately the cost of including old chips in new consoles will only increase as time goes on. It was for this very reason that Sony only included the PS2's Emotion Engine in very early models of the PS3. It would therefore seem highly unlikely that Sony will include a Cell processor in the PS4 or, for that matter, that Microsoft will include the Cell-derived Xenon in the next Xbox. So, is there another option?
The Xbox 360
The other way of achieving backwards compatibility is through software emulation - which is the method the Xbox 360 employs. As far as games consoles are concerned, an emulator is a piece of software that 'tricks' a game into running on a system it wasn't designed for by mimicking the original hardware. The benefit of this method is that it's a lot more cost effective to develop a piece of software than it is to keep manufacturing outdated hardware. The downside, of course, is that the compatibility is much, much lower. This is why the Xbox 360 can only play a limited portion of the original Xbox's library.
In addition to reduced compatibility, emulation comes with other problems; the biggest of which are the difficulty of programming an emulator for very complex hardware, and the power required to run that emulator. Anyone who's used an emulator on their PC will know that the power required to emulate any given console is several orders of magnitude higher than the power of the console being emulated. Complex or obtuse hardware designs only make things harder. For example, the Sega Saturn used a quirky dual CPU set-up that makes it very difficult to emulate.
The complex designs of the PS3's Cell and the Xbox 360's Xenon would make programming an emulator for these consoles extremely difficult, and the power required to run it may be beyond even next-gen consoles. So is there any hope at all for backwards compatibilty?
Streaming may save us all (kind of)
There have been rumours floating around lately that Sony may leverage Gaikai - who it purchased last year - to provided a streaming games service
to PS4 owners. Specifically, the rumours say, the service would allow the streaming of PS3 games - eliminating the need for emulation or old hardware. The painfully obvious problem with this system is that it would surely require a payment of some kind. Whether it was a one off cost per game or some kind of subscription it still eliminates a big benefit of traditional backwards compatibility; namely, that you can play your old games at no additional cost.
Whatever the outcome, it seems that the days of simply shoving your last generation disc into your new generation console may well be over. It's not all doom and gloom, though. A game streaming service done right could resemble a kind of Netflix for games. Having instant access to almost every game from your chosen console makers back catalogue, for a monthly or yearly fee, would surely be worth paying for. Yes, the fact that it would require a constant internet connection wouldn't be ideal, and it would be a painful transition in the short term, but it could become something beautiful. Or, you know, it could collapse in a horrible smoking heap of licensing issues and lag. Only time will tell, and tomorrow Sony will tell us what's really happening for the first time.