What would your ideal HP calc look like now?

[sylvandb]

Mechanical components like a keyboard are more easily justified in spending for quality if they are part of a system that is designed to be upgradeable, not disposable. That's why I have $100+ cherry keyswitch keyboards on my three primary computers instead of the typical $10 (or less) keyboard switches. It's also why none of those keyboards were originally purchased for use with their current computers.

I envision a calculator as three related modules. Each of which would ideally be individually replaceable/upgradeable (within constraints imposed by the other two).

As the mechanical module I'd consider paying $100 for a pocketable case and keyboard with room for 2-3 AAA's and to mount reasonable electronics and a display inside.

The battery might be AAA's or a LiPo.

The electronics might be a anything from a small microcontroller to a small application processor as used in a smart phone.

The display(s) might be anything from a special calculator LCD, or LEDs, or a standard character LCD up to a 5in or larger 1080p touchscreen in a facing fold-over expansion case. It depends on the electronics...

The display(s) needs to work with the electronics.

The electronics needs to work with the keyboard and the display(s).

The keyboard needs to be of high quality.

Maybe this could be prototyped with tactile switches, FDM printed keycaps/cover, and in an extra thick case...