Name:		Fast Bresenham implementation in 65816 assembly
 Author:	FTA
 Written:	1991
 Summary:	The line drawing algorithm used in Arc3D
 Description:

 Oddly enough, there were actually two of us working on fast 3D libraries
 at the same time.  The other guys had pulled the line drawing code out
 of an FTA (Free Tools Association - a bunch of hackers in France) demo,
 so I went ahead and pulled it out of their code.  Turned out to be much
 faster than mine.

 I haven't tried implementing Abrash's variant, but I suspect it wouldn't
 do much (if any) better because of the limited number of registers.