There are techniques out there for running TAS input files against real hardware for most of the common platforms. Some of the TASes on tasvideos.org are specifically flagged as "console verified" [1], indicating that someone's confirmed that they don't depend on emulator quirks.

[1]: http://tasvideos.org/ConsoleVerifiedMovies.html

Thank you, that's just the sort of thing I was curious to look at.

bsnes is now distributed with / renamed to a project called "higan", which is a multi-system emulator. See:

http://byuu.org/higan/