TVM formula error in programming manual?

[dm319]

Thanks all, really enlightening. Thomas, thank you for the break down rearranging that equation! I did something similar but it was so messy comparatively. Yes, the LBL10 subroutine calculates those things, and leaves a couple things on the stack (like PMT cofactor) for the other subroutines to use. To be honest the code is quite a mess. There's quite a nasty fudge where a safe number is put into N to prevent an error for an uneeded calculated variable, just before calculating N. I don't know why that upsets me so much.

Albert, your links are a whole new level of rabbit hole! I sadly don't understand much of it. What is N-prefix on those variables for?

So far my calculations seem to work fine. My biggest issue is with the UI and trying to simulate the solver. I'm using a regular program menu, but wondering if I should switch to the varmenu, which gives me the advantages of being able to 'peek' at the variables, as well as a persistent menu. It also seems to work more reliably than hardcoding menu/solver behaviour. But I can't change modes easily with a varmenu.

On a more meta-level, is there a proper code editor for this kind of RPN? Does vim support it with syntax highlighting for example? What do people do? I got such a headache from scrolling up and down looking for LBL 'X' on my DM42, and trying to type in stuff using the soft key menu or alpha layer was quite a headache.