Plus42 is an advanced scientific programmable calculator, based on
Free42 (a complete re-implementation of the HP-42S scientific
programmable RPN calculator) and adds:

- A Larger Display, with 8 rows and 22 columns (131x64 pixels) by
  default, which the user may resize at will.

- Algebraic Expressions modeled after those used on the HP-27S and
  HP-17B/19B.

- Attached Units and unit conversions modeled after those used on the
  HP-48/49/50 series.

- Directories for more organized storage of programs and variables.

- TVM and amortization tables.

- Two-dimensional Plotting of functions, with ability to zoom and pan,
  and find integrals and roots from points in the plot.
