what is the exponential range of dolphin is it    x e_+256

I assume you mean the range that can be represented by the Float class? If
so then as it states in the class comment Dolphin's Floats use the standard
IEEE-754 double precision representation. Float class>>fmax answers the
maximum value, approximately 1.8e+308, and Float class>>fmin answers the
smallest representable value, approximately 2.2e-308.

Regards

Blair