This hack enables 5-digit, 10,000+ damage/healing. It's capped at 32000 because the total is stored in a 16-bit, signed integer, creating a possible range of -32768 to 32767. I rounded it off to (-)32000 for aesthetic reasons.
https://www.youtube.com/watch?v=6CBgOeR3O1U
This is an updated bugfix and improvement of the previously-titled hack "Displayable 32766 damage/healing". It includes headered & unheadered patches for the Final Fantasy III (U) (V1.0 & V1.1) [!] ROM.
It squeezes 5 digits into 4 tiles, hence the custom font (the original font would have created digit overlap in this case). It's done this way because there is not enough room in the VRAM or OAM for a 5th tile. The tiles are stored in 4bpp, and the digits are squeezed into 4 tiles. This makes the process of assembly-coding somewhat tricky.
I had to revise the custom assembly code twice because it wasn't efficient enough, causing interrupts (NMI) and invisible digits. Furthermore, spells that hit multiple targets (e.g. Quake, WWind, Merton) use different routines for simultaneous display and trigger the interrupt bug more frequently. First, I tried a WAI (wait for interrupt) instruction, which only worked in Snes9x, not ZSNES. I finally managed to fix the issue in both emulators by disabling non-maskable interrupts entirely (STZ $4200). If you experience graphical glitches or invisible digits during simultaneous digit display, it's most likely an interrupt problem. As far as I can tell, this has been fixed.
Special thanks
v1.5 UPDATE (08/20/11): fixed horizontal alignment for 1 to 4 digit display
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OVERKILL 32,000
Author: giangurgolo
Released: August 13, 2011
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This is an updated bugfix and modification of the old hack originally titled
"Displayable 32766 damage/healing".
Includes headered & unheadered patches for the Final Fantasy III (U) (V1.0 & V1.1) [!] ROM.
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DESCRIPTION
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Basically, this patch makes FF6 capable of displaying 5 digits when 10,000+ damage/healing
is dealt. Only up to 32000 (#$7D00/#$8300) damage/healing is allowed because of negative
numbers using the values 8000-FFFF. Also, since damage is stored as a signed short, only
15 bits are available (the 16th bit is the negative bit, ie. healing). Which is why more
than 65535 (#$FFFF) damage is not possible in this scope. This can display anything with
5 digits, though, so if omeone can make a hack moving the healing bits to a different
memory address, allowing for this hack to deal up to 65000 damage, it would be welcomed!
What it does is squeeze 5 digits into 4 tiles. This is why the digits are of a custom font
because the original font would cause an unappealing overlap of digits, making it harder
to read. The reason why it is drawn like this and not 5 digits in 5 tiles is due to VRAM
issues concerning space partitioning. There is not enough room in the VRAM (nor in the
OAM) for a 5th tile to be used since multiple values are stored, forcefully occupying the
entire block reserved for damage/healing values.
To do this in ASM with 4bpp graphics was not trivial but quite difficult to figure out. I
had to revise it twice because the code wasn't efficient enough to prevent an NMI from
interrupting it before it was done. Spells that hit multiple monsters (eg. Quake, WWind,
Merton) display 5 digits too, and use different routines since it involves showing several
damages simultaneously. This was causing interrupt problems, but I put a WAI (wait for
interrupt) at the beginning of the new code and it seemed to have fixed it at first.
Actually, it only fixed it in Snes9x; not in ZSNES. Disabling the NMI (STZ $4200) instead
of WAI finally solved the issue in both emulators. If you get weird effects or invisible
results on screen when there's multiple damages/healings it probably has its origins in
the interrupt issue. As far as I can tell, that has been fixed but nothing is certain.
Special thanks to Imzogelmo for the feedback and beta testing, as well as assassin17 and
Terii Senshi for the offsets of the damage truncation and compressed battle numerals. Also
credit goes to Novalia Spirit for finding several bugs with the draining spells, HP/MP
recovery items, and HP/MP display problems in the battle submenus.
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F.A.Q.
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Q: Why not just use 5 tiles instead of trying to squeeze them into 4 tiles?
A: This is what was attempted many times before it was decided it was impossible.
There are two reasons why it won't work:
1. The VRAM does not allocate enough space for storing a 5th digit for all of the
damages which can be displayed simultaneously on the screen.
2. The OAM does not allocate enough space for storing a 5th digit.
Therefore it is probably safer and simpler to continue using 4 tiles for the reasons given.
Q: Why only 32000? Why not 99999?
A: Total damage/healing is stored in two bytes, and the highest number in two bytes is 65535.
Q: Well, why not 65535?
A: As inferred in the description above, the highest bit is set for healing. Therefore, the
hex values from 32768-65535 are used for healing. In hex, they are negative values and
healing is basically negative damage. Thus, anything over 32767 cannot be displayed.
Q: Why not 32767?
A: Some of the upper values are used for other more obscure things, so it is safer to stick
with a nice round number like 32,000.
Q: Is it possible to do up to 32000?
A: It is very easy. In fact, it has been proven that it is mathematically possible to do over
100,000 damage given the right stats, equipment and spells.
Q: What's the point? Isn't 9999 enough?
A: On any other game where it is much harder to deal so much damage/healing, such as FF5,
probably so. But with something like FF6 where the ease of hitting the damage/healing cap
of 9999 is so high, the desire for something greater is somewhat justified.
Final Fantasy III (USA).sfc - NOINTRO
CRC32: A27F1C7A
MD5: E986575B98300F721CE27C180264D890
SHA-1: 4F37E4274AC3B2EA1BEDB08AA149D8FC5BB676E7
SHA-256: 0F51B4FCA41B7FD509E4B8F9D543151F68EFA5E97B08493E4B2A0C06F5D8D5E2
