|Yet another pocket RPL idea...|
Message #1 Posted by bhtooefr on 19 Mar 2011, 6:45 p.m.
So, I'm thinking about how a pocket RPL calculator could be done. (While I don't really do programming on my 50g, I do like using an RPL calculator. And not just because of the infinite stack. I just wish the thing were smaller.)
The basic idea would be a hybrid between the 28C/S capabilties, the 48S/SX/G/G+/GX keyboard, and something like a 42S or even smaller form factor.
(This thing, I know HP wouldn't ever produce it. However, who says someone else can't? There's enough public documentation out there that it's likely possible to make something that's compatible with user and potentially even system RPL, without infringing on HP's intellectual property.)
So, the first thing is... make keys smaller, and go back to a 4-line display. With modern technology, this'll make a nice small handheld. I actually like the keys on my BB Curve 9300 a lot, for tactility, so something like that (but bigger, preferably) would work nicely.
As for keyboard layout, a few changes that could be made:
- Menu disable button. On a 4 line display, this is EXTREMELY useful for viewing more stack.
- Move the arrow keys up into the softkeys, and they're functional whenever the menus are disabled. This is how the 28C/S do it.
- If possible, remove a row of keys, merging all of their functions with the remaining keys, and moving keys into a logical layout. This'll allow keys to be a little larger, or reduce the form factor further. It'll also be only one row more than the 42S and other calculators that are known to do it.
- If you do 3, then you might have to move Alpha keys around. Potentially a 42S-like solution as an OPTION (not necessarily a default, or maybe a mode that uses both - when hitting Alpha, you get the alpha menu and the alpha keys work as well, and hitting an alpha key gives you 48/49/50-like behavior and the alpha menu goes away, whereas using the alpha menu gives you 42S-like behavior) would work, too.
Hardware... use an ARM7 microcontroller that has a built-in LCD controller, and you're good to go, CPU-wise. LiIon battery would be nice, with USB charging and data, but a couple button cells would probably work, too. (And, you could underclock it significantly to save power - if you're doing a re-implementation of RPL, rather than using HP's actual firmware, you don't have the emulation overhead that the HP calculators have.)
Theoretically, I'd think this thing could be in the 35s pricing ballpark, maybe a little more, if you didn't have to worry about cannibalizing 48gII and 50g sales.
So, anyone interested in making this happen? (For that matter, that includes HP.) Unfortunately, I don't have the skills to make it happen, just some ideas for something I'd like to see.