Well it's been a while since I've done any real hacking in FFIV, and I wanted to get back into the groove of things. I managed to find the location of Ether's value (outside of battle) and how the game reaches it's value. All v1.1 ROM's for any ROM mentions.
The first thing the game does is draw a value from
0x0F9747 - A simple 01, then using the 0A ASM instructions at 01A604, 05, 06 (Which tells the game to continue to accumulate) it continues to boost that 01 to 02, 04, 08, 10, then it loads it somewhere else and accumulates it again to 20 and for it's final accumulation it adds 30.
I was always under the impression that Ethers outside of battle also restored random amounts of MP, but no. It is a static 48 (AKA Hex 30) If you change the value at 0x0F9747 to 02, Ether1's will then restore 96 MP, and so on and so forth.
In ROM this is located at...
0x079947 - 01 to anything you like. I suppose in theory it should be possible to modify it's accumulation phase as well. but as of yet I'm not sure if any other item uses that. (or this 01 even)
Hopefully I'll be able to find the rest of the other healing items in short order.
Hmm... the more I look at this surrounding data, the more I see a pattern emerging...
0x079947 - 0080 2001 6415 - Data involving Ether1
0x07994A - 0080 2003 6415 - Data involving Ether2?
And I see plenty of other similar data formations. I'll have to take a closer look at all of that.
2 Since I felt I had some good momentum going, I decided to look not just for healing items, but the stat boosting items.
So far I've found Soma Drop's location... and within that given space another pattern emerged to show me the location of the Silver Apple (Golden is conspicuously missing...)
This was done with a simple breakpoint on Rydia's Max MP that when it was written to. I was taken to the end of an instruction block, but becoming more familiar with this game's programming I had a feeling I could simply trace backwards slightly and find it (or at least find another lead) and indeed I did. It was just in the basic instructions without any crazy jumps or loops like they did with healing items.
0x01A754 - Silver Apple's amount of HP Raising - 32 (50)
0x01A761 - Soma Drop's amount of MP raising. - 0A (10)
I'll see what's up with the Golden Apple if I can.
3 Well that didn't take long. Looks like, for whatever reason, Golden Apple is placed roughly 20 bytes above the other two stat items. Same data formation though.
B1 60 18 69 64 00
0x01A73A - Golden Apple's amount of HP Raising 64 (100)
The aforementioned three are located in ROM at...
0xA93A - Golden Apple - 64 (100)
0xA954 - Silver Apple - 32 (50)
0xA961 - Soma Drop - 0A (10)
4 Oh! I'm a fool! The data for healing items had already been found before. Ah well, at least the stat boosting item info is new (I think?)
5 Ah, here's something a bit interesting. I think you can very easily change what stat you want the stat boosting items to raise.
09 00 B1 60 18 69 64 00 - That 09 00 At least is telling the game to write to HP.
0D 00 B1 60 18 69 0A 00 - The 0D 00 is telling the game to write to MP.
If you look at normal character data...
09 of 40 Bytes is the Max HP Byte
0D of 40 Bytes is the Max MP Byte
So if my thoughts are correct you can increase any stat you like with these items. (If I'm not mistaken, maybe even change classes too) this will require some experimentation.
Looks like I was right. Rydia eating the Soma Drop changed her name to Yang and gave her Kick.
This does have very interesting applications if one wants to take the game in a new direction.... (Possibly, since it doesn't seem to kill Levels, have a set of 3 jobs you can change into at will.
And even better because the game gives two bytes for these to play around with you can change Class and Character without any ill side effects (well they'll have the stats and equipment of the person they switched from, since you are changing only two bytes) but they'll have their own abilities at least. However the problem that you may have noticed by now is something I didn't take into account. It only increments, it doesn't set a value. Now there may be a way to change that, but as of now I could see these items as only working towards "class upgrades" or some such.
7 Well that issue is solved... truly the Heavens smile on me today. First byte change and boom, exactly what I'm looking for.
0D 00 B1 60 18 69 0A 00 - All you have to do is change 60 to 00. That will get rid of the Increment and the game will read it as an overwrite. Now you can choose whichever 3 classes you like and switch to them freely (It should be noted that all that will accomplish is changing Sprite, commands, and available Equips,(possibly Level Ups as well, I haven't tested that) however you will still be equipped with whatever you had originally, (So say you wanted to change Cecil into a Mage, he would still be equipped with all of the Dark Knight gear if you used this method) Also there is no way (without making a special event place for it) for the game to know who belongs to what class. So if you use... Let's say a Mage book on Yang. That will be Yang, from now on, even if you only planned on having it be given to Cecil.
Really this plan works out Marvelously for a Solo Mod, but when there's a party involved, yeah... things get messy. However you can still increase any basic stat you would like with this, just use...
http://rb.thundaga.com/ and JCE's hacking document to change the stat you want to increase or set.
As great as Geigers is, sometimes it's just so infuriating "not allowed to go into certain ranges where battle data is contained, grumble, grumble..." so back to Cheat Engine for now, which was not made for SNES games and makes actually doing much other than memory editing a bit tricky...
However I looked up how the game puts various equipment on. The breakable bit, as earlier mentioned, does work for non-arrow items, but the issue is that the game will only ever equip one of an item on. But every inventory slot has an extra byte which would be used for diminishing uses of an item and setting that to 2 or above will show a plain number next to the item. This leads me to believe that it is looking at an index for the Arrows specifically, but if that range can be expanded to all weapons, well there might be an interesting game...
9
I think you'll like this one, PinkPuff (for data purposes, I can't see too many people really making use of it's potential)
No tricks here, just a little simple hacking (just one byte change actually)
I was encountering difficulty discovering where the game was looking to decide whether to add a whole stack or just one to weapon counters, I then eventually found the start of the process at 0x01C12E I was at first searching for BNE (Break if Not Equals) since I thought that would be the defining amount and was indeed looking for item 54, which is Iron Arrows. Lo and behold it seems I was looking for CMP (Compare Accumulator with Memory) and noticed that 54. I changed it to 00 and every weapon (and only weapons) equipped
became equipped in bunches. Which means that my Shadow Sword experiment from way back finally succeeded and you can make SaGa-esque weaponry now!
Down the line I would like to try to make it to where using the weapon as an item would consume it. But that's that! I think with this you have a reason to include the "Break if used" byte included on weapons.
The byte is contained at
0x01C234 in RAM and in ROM at...
0xC434 Just change the 54 to whatever index you like and the items will be equipped in bunches.
Hopefully I can find the mystery to Two-Handed ness as well soon.
