HP HP-16C - Section 3: Number and Display Control; Integer Mode; Number Base Modes

Section 3
Number and Display Control
Number representation in the HP-16C is much more versatile than
in other calculators. This section will discuss the different aspects
of integer number use and display: number bases, word size,
complements, number ranges, and the resulting displays.
(Floating-point format is described in section 5, Floating-Point
Numbers.) The formats you specify are preserved by Continuous
Memory.
Integer Mode
The number base modes ([HEX], [DEC], [OCT], and [BIN]) operate
strictly in Integer mode (that is, using integers only). Fractional
decimal numbers can be used in Floating-Point Decimal mode,
described in section 5. Pressing any of the four number base keys
establishes Integer mode.
Number Base Modes
There are four number base modes used by the HP-16C in Integer
mode for purposes of display and digit entry: Hexadecimal (base
16), Decimal (base 10), Octal (base 8), and Binary (base 2). An h, d,
o, or b to the right of the eight-digit display indicates the present
number base mode. The calculator defaults to Hexadecimal mode
when first turned on or when Continuous Memory is reset.
Pressing [HEX], [DEC], [OCT], or converts the display to that
number base in a right-justified, integer format. Digit keys pressed
are interpreted accordingly: the calculator will not respond if
you attempt to enter an inappropriate digit (such as a “3” in
Binary mode). In addition to the digit keys [0]to [9], Hexadecimal
mode uses the keys [A]to [F], appearing in the display as A, b, C, d,
E,andF.
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