DB48X: HP48-like RPL implementation for DM42

[c3d]

(10-01-2024 10:49 AM)tdh79 Wrote:  

(07-10-2023 12:07 AM)Helix Wrote:  As I find RPL superior to RPN, this project could justify the purchase of a DM42.
And I like very much the interface!

I have some basic questions:
- how to quickly access the variables menu? I don’t remember seeing it in the video.
- will comments be possible inside programs, apart from the inelegant "text" DROP ?
- will list processing be available, like in the HP48 G/GX or the HP50G?
- I know it’s very premature, but if variable floating-point precision is implemented some day, will it replace the fixed floating-point precision library? I don’t like the idea of scarifying speed to gain useless precision.

RPL different from RPN? I thought one was a programming language and the other a method for inputting data?

In contexts where you contrast them, it's typically to oppose "keystrokes" programmable calculators, called "RPN", to the Reverse Polish Lisp ROM Programming Language known as RPL. It's also to distinguish calculators with a 4-level XYZT stack that fills with T when you consume values from later RPL models where the stack can grow arbitrarily and errors out if empty. Historically, RPL also implies support for algebraic and symbolic expression evaluation, named variables, structured loops, and a wide variety of data types.

RPL descends from RPN, and some simple RPN keystroke programs translate quite naturally into RPL. Anything that involves GTO/LBL loops or worse yet the horrible ISG/DSE instructions will definitely be harder to convert from RPN keystrokes to RPL :-)