I was expanding out all the weapon data this evening and I noticed something interesting in the Main Data on Byte 0x02 (The Attack% or "Accuracy" Byte).
Every weapon that was originally coded to cast a magic spell (whether it works in FF-II or not) has the MSB flipped on the Accuracy byte. (I noticed this because the accuracy shouldn't be over 100%, for example it's $A8 for the Rod.)
The pattern definitely corresponds to weapons that cast magic. No weapons that do not cast magic have the Accuracy MSB flipped, with only one exception. The Samurai/Yoichi bow has it flipped. Making me think that weapon may have originally had a spell associated with it but the developers managed to disable it and leave no trace. The only other bow that has the bit is the Elven Bow, which is supposed to cast Shell.
The only inverse exception is that the Power staff does not have the MSB flipped, even though it was supposed to cast Berserk... Every other spell casting weapon does.
I don't know what this means...and I'm not sure what it does??? I do know it's not required to make a spell work on a weapon as I've set weapons with magic without altering the accuracy value.
My first thought was that perhaps it makes the spell always hit?...I haven't tested exhaustively, but my early opinion is that it doesn't appear to. I have the "Doom" spell set on the Deathbringer sword and it always hits, no matter what, without accuracy's MSB flipped. (I also don't think I'm going to leave that spell on that weapon, it's kind of a big cheat to keep using the spell that way).
