RCL-57 now available at the App Store

[vaklaff]

(08-26-2022 06:02 AM)Dan C Wrote:  Wow, thats way beyond my knowledge! Thanks for explaining, i was thinking making an CASIO fx-4000P app, cuz thats my fav. calculator. But i realize know that i newer can do it

Good taste, it's a beauty :-)

Don't let the perceived complexity stop you.

If you are a beginner, start small. Try to write a simple four-banger, without any operator precedence. Think about its state: maybe it could be represented by just two numbers (regX = the number on the display, lastX = the previous one) and one character/symbol for the operation (+ - * /) the two. Now each key press changes the state. How? Draft a graph or table of the changes. Implement with a simple UI. Yay, your first calculator!

What about adding an independent memory? Probably a new number in the state, regM. More keys that usually go with it. Let's rethink the graph/table ("state transitions" in the lingo). Implement.

Operator precedence. Does it need new data in the state? What it means for the state transitions?

After a short while, with the experience growing, the previous comments will start to make sense to you. You'll be in the position to decide what you actually want to achieve. An fx-4000P lookalike that behaves similarly but not precisely the same (e.g. different precision)? A bug-to-bug same-precision faithful simulator (not doubt more complicated state)? An emulator, a somewhat different beast (you "implement" the HW and then let it run the firmware copied from the calculator)?

I hope now it sounds much less scary :-) Good luck!
v.