Scientific RPN Calculator (with ATTINY85)

[deetee]

Hi Pauli!

After some days of work I am proud to show you a new (much better version of ScArY) with a code size of 8130 bytes.

I did not finish testing and documentation - but maybe you can view the attached file for improvements, bugs and optimization?

I made this major changes so far:
* Using a stack array (X, Y, Z, T, STO) now which works well with your push/pull/memmove solution.
* Changed the switch/case Statement to an if/elseif structure.
* Saving the calculator state (stack, brightness) to EEPROM when activating the screensaver (keys: f-f).
* Save up to 41 user defined constants/numbers with up to three characters per number to EEPROM. Browsing and loading this saved constants with cursor keys or direct number input.
* "Type-Recorder" function: Record 4x51 keypresses to EEPROM and replay them via user menu (a, b, c, d).
* Changed keyboard layout to bring important functions (menu, const, sto) closer to the f-key.
* Abandoned ROTup for saving codesize and faster menu entering.
* Abandoned my loved annuity function to save codesize and to minimize the number of menu lines. I can "program" this function later with the type recorder function.
* Due to your recommendation I extended the faculty function to a gamma function (according to the Nemes formula).

There are still some bytes left and I am sure you will find some more and have some ideas how to use them.

Thanks in advance
deetee