A computer game emulator is a piece of software, or a program that makes playing video games that were made for one specific hardware platform playable on other hardware. Most types of emulators are developed to enable playing classic video game titles like Mario, Donkey Kong, Zelda playable on PC’s and current generation video game consoles. Other types of emulation often used today are cross-platform emulation (emulating the behavior of one console on another one, to make playing games for Sony Play Station playable on XboX for example), and emulation to enable playing games that are in different languages or even to hack modern games. Emulators are also used for educational purposes, and they make keeping software development techniques that we’re used on classic systems alive possible.
Back in the nineties, personal computers became powerful enough to make attempting to recreate the behavior of some entertainment consoles technically realistic and entirely feasible. The first console emulators appeared in this period. The emulators of that time were often incomplete, buggy and unpredictable, but this is understandable, considering that most of them were non-commercial and almost amateurish attempts at hardware emulation. Another reason why those early attempts were mostly failures was that it was rare for console manufacturers to publish technical specifications for their consoles, forcing would be emulator developers to reverse engineer the consoles on their own. Most common platform that was emulated at that time, and the one for which the most advanced emulators were developed early on was Nintendo – specifically the Nintendo Entertainment System, the Super Nintendo Entertainment System, and the all popular Game Boy.
Some of the early popular emulators of that era were Virtual Game Boy, iNes, Pasofami and Super Pasofami, and VSMC – all for various Nintendo’s consoles. There were even attempts to recreate the behavior of Nintendo’s Entertainment System on then modern Sega Mega Drive, making this the earliest known attempt to recreate the behavior of one console on another, or cross-console emulation.
The sudden spike in the popularity of console emulation on PC’s made playing games that were exclusive to the Japanese market and hence never released in the United States due to Nintendo’s copy write policies possible for a huge community of gamers. The rapid rise in interest in emulation also helped grow communities dedicated to ROM home brewing, hacking and fan translation. The release of projects such are fan made translations of popular Japanese language only titles made games that would never see playing time outside of Japan into huge hits, and some of those projects are in use even today.
Unfortunately, copy write laws and licensing issues are still the main issues that plague the emulation community. Under the US legislation, in order to posses and use a dumped copy of a BIOS, you need to legally obtain the original machine that the BIOS was developed for. For a lot of platforms, this is no longer possible, but several emulators are able to run without the actual BIOS file, by simulating the function of the BIOS itself.