Official FF6: Beyond Chaos thread (randomizer)

Go to Emulation > Settings to find the options to turn rewind on. You'll see "Rewind Buffer" and "Rewind Granularity", which you'll have to set to non-zero values. In order to bind the rewinds to some input key, you'll need to go to Input > Hotkey Configuration and select Page 2. You should see a "Rewind" field.

If you see none of these, you need to update SNES9x to a newer version.