I'd like to throw out a few ideas regarding solving differential equations on the Prime.

1. The tick mark used to denote differentiation of a function is too many keystrokes away (Shift -> Chars -> ' -> OK). In fact, it took quite a while to hunt it down. It is one keystroke on the HP48,50 and two strokes on the HP49. Perhaps I can redefine a key on the Prime?

Bonus points: have the "Template" key pop up symbols/characters that are relevant to the function currently being entered on the stack. For instance, if I've chosen desolve(), have the template key display the tick mark along with the other things already displayed.

2. I'd like to plot the solution of desolve(). CAS mode uses lowercase variables and the plotter wants uppercase. I've tried limping along in the CAS, explicitly typing uppercase X for my variable... and it "works"; but I feel I'm abusing the way the CAS was meant to be used. I also feel that at some point I'll screw up and my calc will substitute a numerical value of X into my expression and I'll never be the wiser.

So what I'd like to do is just use the CAS as intended; with lower case variables. I'd like to write a small app, lets call it "PlotCAS", that will copy my CAS expression off the CAS stack, replace all lower case x variables with X, and store the result in variable G7. Not sure if it's possible... "find and replace" method might end up clobbering any math functions whose name contained the letter x? Symbolic side of the calc may substitute 0, or the latest numeric value for X, for all instances of X after the substitution?

Not expecting anyone here to program it for me... just want to know if it is feasible.