Displayable 32,766 max damage/healing hack
Author: giangurgolo
Released: Feb 14, 2011

Includes a patch for both v1.0 and v1.1 of the Final 
Fantasy III (US) [!] ROM. Apply to a headerless ROM.

Here is a link to a demonstration video: 
http://www.youtube.com/watch?v=gW_ympIie-E

Basically, this patch makes FF6 capable of displaying 
5 digits when 10,000+ damage/healing is dealt. 
Only up to 32766 (#$7FFE/#$8002) damage/healing is 
allowed because of negative numbers using the values 
8000-FFFF. This can display anything with 5 digits, 
though, so if someone can make a hack moving the 
healing bits to a different memory address, allowing 
for this hack to do up to 65535 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.

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 display 5 
digits too, which 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. If you get weird 
effects when there's multiple damages/healings on 
screen it was probably because of an NMI. 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 assassin17 and Terii Senshi
for the offsets of the damage truncation and
compressed battle numerals.