( -- ) ( F: r
-- ) or
Display, with a trailing space, the top number on the
floating-point stack using engineering notation, where the
significand is greater than or equal to 1.0 and less than
1000.0 and the decimal exponent is a multiple of three.
An ambiguous condition exists if the value of BASE
is not (decimal) ten or if the character string representation
exceeds the size of the pictured numeric output string buffer.