Table of Contents
Section b
Floating-Point Numbers
To cover other aspects of computing, the HP-16C was designed to
perform floating-point decimal arithmetic also. In Floating-Point
Decimal mode, numbers are left-justified and the word size is
automatically set to 56 bits.
Note: Numbers in Floating Point mode and Integer mode are
represented in two different, incompatible formats.* There-
fore, any values stored in the storage registers in one format
are not meaningfully converted when the calculator switches
to the other format. Their integrity is retained, however,
when the calculator is restored to the original mode.
Converting to Floating-Point Decimal Mode
The
(floating point) function establishes Floating-Point
Decimal mode and converts the contents of the X- and Y-registers
(as explained below) to a floating-point decimal number.
Pressing
{0to 9, (-]} will set Floating-Point Decimal mode.
The number you specify determines how many decimal places will
be displayed; specifying [-] will set scientific notation. (If the
calculator is already in Floating Point mode, no further conversion
of the stack takes place.)
Conversion in the Stack
When you make the conversion to Floating Point mode, you might
want to be able to retain a certain number for further use. The
HP-16C provides a conversion routine that allows you to retain and
reuse a value from Integer mode when the calculator switches to
Floating Point mode. Upon executing
in Integer mode, the
numbers in the Y- and X-registers are converted to the floating-
point decimal equivalent of (y)(2*), which is then placed into the
X-register. The Y-, Z-, and T-registers are cleared.'
* Floating Point mode in BCD (Binary Coded Decimal) form and Integer mode in binary
form.
t Appendix D provides a program for a conversion between the proposed IEEE floating-
point binary format and HP-16C floating-point decimal format.
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