====== Floating point support ======
Summary of the discussion in 2004 (without IEEE 754-2008 knowledge of course):
  - An agreed floating point number format
  - 6502 conversion routines from int <-> float and back
  - 6502 routines to support + - * / < > <= >= == != operators
  - changes of the compiler, assembler and linker
  - 6502 ASCII <-> FP conversion functions (e.g. for scanf/printf)
  - A 6502 math library (pow(), exp(), sin(), cos(), ... the works)

===== 32 vs. 48 bit =====
                 32 bit                        48 bit
    -----------------------------------------------------------------------
      "Standard" (whatever that's      Better precision.
      worth).
                                       Will meet the ISO C requirements.
      Needs slightly less memory and
      is faster.                       Format can be optimized for 6502.
      Compiler can use native
      fp routines. But: Limits
      number of host platforms.
      Doesn't meet ISO C               Needs slightly more memory and is
      requirements.                    slower.
      Less precision.                  Compiler needs fp library. But:
                                       will work on all host platforms.
      Binary format is given and
      we have to live with that.       Implementation needs more code, so
                                       programs have a larger memory
                                       footprint.
      Is suboptimal. wrt exponent      could be made optimal wrt.
      processing (8 bit covered in     exponent processing
      2 bytes)

===== Conclusion =====

  * support the ISO C standard: IEEE 32 bit format
The C standard allows setting errno, raising an exception, or just ignoring
the condition for most operations. The standard does not require NaNs and
infinite values, so it may be an option not to implement them, because this
removes all corresponding checks in the math functions resulting in smaller
code size. The TMS320 DSP has this behaviour and it's quite convenient.

[[http://grouper.ieee.org/groups/754/|IEEE 754-2008]]
[[http://www.jhauser.us/arithmetic/|IEEE 754 test suite]]
[[http://codebase64.org/doku.php?id=base:floating_point_routines_for_the_6502|Steve Wozniak's implementation]]