It's a good read and since we do some VC games here I found it interesting.
http://arstechnica.com/gaming/news/2011/08/accuracy-takes-power-one-mans-3ghz-quest-to-build-a-perfect-snes-emulator.ars
I read this a long time ago when I was freaking out about my Snes9x GX not playing Yoshi's Island music right, I thought it was because of imperfect emulation, when it turned out it was that my at the time mono TV was only playing one of the sound channels. It's good read about a guy trying to make his emulator work exactly like a real SNES