I can’t leave well enough alone. Tonight I changed the keyboard slightly and added a bit of additional functionality.
The keyboard was updated to change the INV key to 2nd, replacement of the x><t (x exchange t(est register)) with lnx, and the addition of the 3rd key where lnx used to be. You can see the changes above.
The code change was to tie into the 2nd key’s click event and to change its color to indicate when it was toggled into an active state. It goes from light gray to orange and back again. But what’s significant about this is that keys that can change their state when the 2nd key is toggled also change their color and the text on the key itself. This, the lnx key under normal mode conditions becomes the exponential key ex and changes its color to a matching dark orange as you’ll note above.
This addresses a major gripe I always had, and continue to have, with standard key calculators. The keys are “dead” in that they are always a fixed color with fixed text. But with something like a phablet or tablet Android or iOS device, that’s not longer the case. This is a proof of concept for me. Time permitting I’ll add more secondary functions, and even tertiary functions, for the 3rd key.
The idea of an orange/yellow and blue secondary key is an idea as old as the HP-65, which first showed up in January 1974. I’ve just taken the idea and extended it a tiny bit to make it easier for the operator to find additional functions without having to use tiny text above and below a key, or to fill up the screen with lots of single function keys.
If I had the money I’d create a keyed calculator with OLED keys that would do precisely what this app is doing.
Here’s what the 3rd key looks like toggled. There are at present no other function keys it can modify.
The 2nd and 3rd function keys are set back to their primary colors by toggling the respective key, by hitting Clear or Clear Entry, or by performing the indicated operation, such as ex.
I’ve decided to actually move forward to keystroke programmability, but not the way that either TI or HP did it. But first, I need to finish making all the keys fully functional. More to follow…