Quoting this post from @MaryHadALittle : I was puzzled by the existence of a byte and @TGGC recently posted. Reposting here so we can gather info in one place. You mean that they had that idea in the beginning and then decided to scrap that? I would tend to see it that way, but then I'm wondering what we are actually watching when we're reading bits of the M-Roll condition byte (0x06064BD0). Are we absolutely sure that this byte is used for the M-roll? If so, what does the code read?