Conversion of flonums to floating point is correct, and compatible with previous assemblers. Rounding is towards zero if the remainder is exactly half the least significant bit.

`D`, `F`, `G` and `H` floating point formats
are understood.

Immediate floating literals (*e.g.* `S`$6.9`)
are rendered correctly. Again, rounding is towards zero in the
boundary case.

The `.float` directive produces `f` format numbers.
The `.double` directive produces `d` format numbers.