Take gaming for instance.  When I was young, I was playing 8 colour Spectrum games using an old Atari joystick, having to wait 7 minutes for the game to load.  And I loved it.  It required imagination, patience and pinpoint accuracy; many games were so unforgiving, especially considering that there was no real way of saving your progress.  If anything, those early-era games were perfect training grounds for the games of today, and something the next generation of button-bashers have no experience of.

Which lands me nicely to the subject of this article - emulation.  Essentially, emulation allows you to play the greatest games ever devised without digging your NES or Master System out of the attic.  If you remember spending either all your money on playing Star Wars in the arcade (and I mean the original wire-frame game), or all day in the house trying to complete Treasure Island Dizzy, you need to read on.

To emulate is to mimic, which is exactly what emulators do - they make one system act like another.  Some extremely clever and resourceful bods have made emulators to mimic almost all home computers, consoles and arcade machines of the past; NES, SNES, Genesis, Gameboy, Spectrum, VIC-20, Atari 2600, Neo Geo - the list is too numerous to mention.  There is an extremely good chance that the box you wasted most of your childhood in front of has been emulated. 

The mechanics work like so; the emulator is a virtual machine, something which you may hear mentioned when reading about Java (incidentally, Java works exactly as an emulator does).  It sits on top of the operating system, translating all the code in its original form into code that your PC can work with, and vice versa.  A file containing Super Mario Bros is just a load of pointless machine code to a PC; stick a NES emulator between the two, and you’ll be splatting Koopas once again.

There are two types of emulators, namely high level and low level.  Low level emulators are faithful and accurate representations of the original machines - if a program ran on the real machine, it will run on the emulator.  High level emulators, on the other hand, are specifically written to support certain games and programs.  The high level emulators usually exist for the more complex and potentially variable machines such as the N64 and arcade cabinets.  In short, low level emulators are written around the console; high level ones are written around the games.

Because the emulator is translating code between two totally different formats, more processing power is needed.  If you look inside a Playstation, you’ll see a processor on par with a high-end 486.  However, you’ll need at least a high-end Pentium to run Playstation games on an emulator at anything near a decent rate.  This has caused problems in the past, especially with the N64 (this console took emulators into a new era, as I’ll explain later).

As with anything fun, there is a legal issue with emulators; the workings of a console is copyrighted, therefore having an emulator was the same as having a pirated version of the console.  There are exceptions.  Consoles and computers deemed "dead" by their creators become Public Domain (PD) and legal to use for whatever purposes.  The games for that format usually follow suit, but again, exceptions exist, especially for games created by software houses still in existence.  Ultimate made some amazing and classic games in the eighties such as Jet Pac and Lunar Jetman, but because Ultimate are still around (now called Rare), their games are not PD.  Real shame.

Up to 1998, emulation wasn't really a problem.  These virtual consoles were being used illegally, but as mentioned before, these machines were effectively (but not officially) obsolete and therefore not affecting the profits of their respective owners.  As a result, they were more a tool used for nostalgia purposes than a serious gaming activity.  Then, a landmark event happened - UltraHLE was released.

UltraHLE climbed the Everest of emulation at the time - it emulated the N64 perfectly, so much so that Nintendo stepped in within hours of its release on the Internet and took down sites hosting the incriminating material (on the ball as usual, I was downloading UltraHLE within minutes of its release, heh heh heh!).  UltraHLE was a high level N64 emulator though, so not all games could run.  However, it did emulate the better games - playing Mario64 at full framerate on my PC will always be one of those things I will never forget.  People said that it couldn't be done - the N64 was a surprisingly powerful and complex beast.  The authors of UltraHLE got around this problem using the high level solution rather than struggling to emulate the whole thing.

Nintendo went berserk.  In theory, anyone could download UltraHLE and all the games they wanted for free without paying Nintendo a cent.  Nintendo's legal machine was set in motion, firstly targeting the authors of UltraHLE then all websites hosting either the emulator or N64 roms.  This had a knock-on effect for all other similar companies - if Nintendo could be affected by blatant piracy, could they?  A call went up in Corporate America to recognise emulation as illegal, which succeeded.  In the following months, most emulation websites were taken down following legal threats made against the host and/or the webmaster. 

Despite all of this, the first working Playstation emulator appeared, PSEmu Pro.  It was fantastic and fully functional.  It was also a bit fiddly, but once you got all the plug-ins correctly configured for your graphics and sound, it actually ran better than the real thing. 

Soon after PSEmu Pro, a very odd thing occurred.  At that time, all console emulators had been created by people that had a personal interest in a certain system.  In a direct challenge against this norm, the world's first commercial console emulator, Bleem!, appeared.  For around $50, you could own a Playstation in your PC.  The reasoning for this was very simple; no matter if you were running Bleem! or a PSX console, you still needed an original game disk to play a game.  It was simply unfeasible that someone could download 650Mb of PSX game from the web (128Kbit ISDN connection was the fastest link any domestic user could have at this time).  At this point, the PSX console's sales were slowing, and as long as the sales of games were not threatened, Bleem! could only do good.  Sadly, it wasn't a success and didn't take off.  However, emulation had crossed the line from harmless toy to profit-threatening activity.  5 years on, emulation is still restricted; try to find an N64 rom hosted on a website and you'll see what I mean.    

Strangely, emulation has lost momentum on the PC.  The newer consoles are not emulated due to their complexity and protection - lessons have been learnt from UltraHLE, both from a programmer and manufacturer's point of view.  Instead, emulation has taken a tangent to the original idea.  Now, consoles are able to emulate other consoles, an ironic twist hopefully not lost on the console manfacturers.

If you are interested in emulation, check out http://www.pure-emu.com and take a peek at the list of available emulators.  Legally, you must own the console and any roms you aquire from the web, so be warned.