
Calc98
Calc98 is a small but very powerful scientific calculator, with lots of features:
Version 5.3 (totally free)
RPN
Base-n, hex, octal and binary modes
Scientific/Engineering Functions
Matrix/Array Functions
Complex Numbers
Statistical Functions
Financial Functions
Time functions (calculations, watch, countdown, etc)
Angles (degrees, minutes, seconds)
Roman numerals (!)
Periodic Table of Elements (!!)
Units Conversions
Physical Properties and Constants
Editing Properties, Units and Constants
System Functions
Miscellaneous Functions
Keyboard Accelerator
International Versions
Version 5.6 is cheap and has a lot of new functions:
Better RPN logic and visible stack
New modes for fractions and feet/inches
IP address calculation mode
Better financial functions
New interactive financial rates dialog
Customised calculator themes
More data than ever, including new particle physics data
Updated matrix and complex modes
etc.