Plus42 Equations, Preview Release

[Thomas Okken]

New update:

1. More support for the new row of keys in the new Plus42 skin. Among other things: all keys have assignments now, and DIR.FCN and UNIT.FCN are proper menus now, not just shortcuts to the corresponding catalog subsections. But the GRAPH and TVM menus are still empty...
2. Updated the Plus42 skin as well, with new and improved legends. (The skin is still a separate download, it's not yet compiled into the executable.) The new legends still don't look good, but a bit better than in the previous version.
3. Attempted fix for the Android version, where ROW+/- and COL+/- didn't work for skins loaded with Skin: Other.

Things that have me scratching my head:

a. I wonder what fonts I should use for the skin? Right now I'm using Arial Narrow Condensed 28pt for the key caps, and Arial 19pt for the shifted legends. They're close, but not quite right. The letters on the key caps are a bit too narrow, and the shifted legends are a bit too heavy.
b. If you are in the UNITS catalog and you go to the UNIT.FCN menu, you lose your place in the catalog, because both exist in the same menu level. It would be nicer if you could use a function from UNIT.FCN and then return to where you were in UNITS. Should I make UNITS into an application menu? That would fix this issue, but then, if you opened UNITS on top of a VARMENU (like the one in the solver), you'd lose your place in the VARMENU. Or should I add a third menu level, between the application menus and plain menus, just for UNITS and DIRS?
c. How should the TVM menu work, for N/I%YR/PV/PMT/FV? Just like a solver menu, where you press a key both to store a value in it and to compute a value, and you press a key with Shift to view its current value, and you can also use STO and RCL on the five parameters? That would integrate nicely with the existing solver menus, but would it match what HP's financial RPN calculators have historically done? (I don't know because I've never used one.)