Approximately related, I find the NumWorks calculator [1] absolutely enthralling. It has a fairly beefy modern ARM Cortex M4 processor which runs an attractive GUI written in Python. And yes, you can write and run Python on the device. The hardware is very well described [2] in human terms and electrical schematics are available. Software is totally open source and the device can be easily reflashed. I'm not sure what I'd use it for, but I've had one on my birthday list for a while.
There's a web simulator [3] online if you want to play with the OS.
Thanks for pointing this out. This is a fundamental and major distinction that can easily be missed—the noncommercial use restriction means that it's tied to this vendor and the people who want to spend their nights and weekends enhancing the vendor's profitability. It makes it really difficult to form a community.
The TI-89 series' CAS is really impressive, particularly since it was released over 20 years ago with automatic equation formatting and a powerful unit subsystem.
The price of this is worth it for the software alone.
I used it as a DOS program well up into the late 90s on my HP200lx... One of the badass things about it, afaik, hasn't been reproduced in any CAS: the quasi-ncurses looking menu made it easy to use on limited hardware and you didn't have to waste time looking things up. I occasionally consider buying one of the TI calculators just to fool around with it again.
It's still my favorite CAS for unit conversions, simple equation solving, checking integrals and derivatives. Part of that is surely the muscle memory of the buttons from using it daily for 6 years, most of that before I even had a phone.
Now I have an emulator with a ti89 ROM on my phone. Best offline calculator app available.
If it runs Python, then couldn’t you use SymPy as a CAS (in addition to NumPy, seaborn, etc. for numerical computing / visualization)?
By the way, I like the idea of this calculator and hope to see more like it. I think something that combined this with ideas from WolframAlpha (natural language CAS, problem explainers and expanders) and Khan Academy (spaced repetition, gamification of learning, progression of tutorial videos, practice and diagnostic problems) would be really powerful. In fact I became temporarily obsessed with the idea of creating this sort of calculator >10 years ago when taking multivariate calculus and struggling to visualize or understand the problems. Yes, you could always use a computer/tablet/phone, but as someone who struggles with ADD, there is a lot to be said for using a constrained learning tool, so that the versatile (read: distracting) devices can be put out of sight during dedicated study time.
I seriously hope someone puts all these tools together in a single package that doesn't force you to get distracted with programming, I don't want to really do more than for example enter "y=x^2" and press "Graph", advanced features can left for later. Kinda like how I don't find a phone a calculator but know it can do so, the default isn't calculating numbers.
There's a web simulator [3] online if you want to play with the OS.
[1] https://www.numworks.com/
[2] https://hackaday.com/2018/05/18/open-source-calculator-teach... (full disclosure, I wrote this)
[3] https://www.numworks.com/simulator/