Is there any documentation related to the implementation differences between revisions of the SNES hardware? I've found all manner of information on various combinations of hardware revisions, but it has all been related to improved video encoders and pipeline. I'm looking for any known details on changes to instructions, including undocumented, or functionality of the PPU.
Specifically, I'm trying to figure out the technical reasoning behind this behavior:
Link to video
While the video itself is not mine, I have a model of SNES that produces the exact same graphical oddities. Stranger yet is that they only occur on the first stage; 2nd and beyond Arthur appears as normal. I don't remember the exact combination of parts in the SNES (it's a full-size 1CHIP, at least), but it doesn't happen on my SNES-mini or older full-size models. I'm curious if:
-Whatever causes these anomalies can be leveraged in other games
-How much it would take to reproduce the same effect in-emulator