With those buttons you can select the number system (radix) you want to
use – Decimal, Complex, Hexadecimal, Octal, Binary.
Here you can select how the decimal and complex numbers
are displayed (with or without an exponent), and also the trigonometric
mode (degree or radian measure). For the binary modes (hex/oct/bin),
the buttons will instead present a word size selection.
This group gives you mouse access to the decimal setting (i.e.,
how many decimals to display), and also the three pushbuttons
Configure, Help and Exit.
αβγ
XCALC buttons
On the XCALC main window there are plenty of buttons that can be
clicked, arranged in groups that can individually be switched on or off
(see configuration):