HP HP-16C User Manual

Section 5: Floating-Point Numbers 59
Overflow and Underflow. When the result of a floating-point
calculation in the X-register is a number with a magnitude greater
than 9.999999999 X 109, +£9.999999999 X 10% is placed in the
affected register (the last three digits of the mantissa are not
displayed). Flag 5 (out-of-range) is set and the G annunciator
displayed.
If the result of a floating-point calculation in the X-register is a
number with a magnitude less than 1.000000000 X 109, that
number will be replaced by zero. Overflow and underflow do not
halt program execution.
Returning to Integer Mode
Integer mode is restored (and Floating Point mode exited) when
you set one of the number base modes.
Conversion in the Stack
When exiting Floating Point mode, the X- and Y-registers undergo
the reverse of the conversion when Floating Point mode is set.
Considering the number in the X-register to be in the form (y)(2%),
an integer y is placed in the Y-register and a power x of 2 is placed
in the X-register. The value for y is defined such that 23! <|y| < 232
unless y = 0. That is, y, the mantissa, is rounded to a 32-bit integer.
The value for x, the exponent, is determined by y such that (y)(2%)
equals the value in the X-register before mode conversion.
The new x- and y-values will be expressed in the number base mode
specified. (In Unsigned mode, the absolute values of x and y are
placedin X and Y.)
The conversion of an integer pair y, x from Integer mode into
Floating-Point Decimal mode and back to Integer mode generally
will not restore the original pair y, x, but an equivalent one.
Example: Convert 1.284 X 10-!7 to a decimal integer multiplied by
a power of 2.
Keystrokes Display ([STATUS]: 2-56-0000)
1.284 1.284
1.284 00
17 [CHS] 1.284 -17

HP HP-16C Specifications

General

Brand	HP
Model	HP-16C
Category	Desktop
Language	English