Here’s an article by the programmer of a popular SNES emulator on why perfect emulation is actually very hard:
Short version: old hardware has all kinds of special cases and exceptions where fairly straightforward emulation fails. Getting these cases right consumes more processing power, and he estimates truly perfect emulation of a SNES would require around a 3 GHz machine. Worth a read if you’re interested in understanding why emulation of even old machines isn’t perfect.
Who’s interested in ‘perfect’ emulation? All we want is ‘good enough’.
