Yes, calculators are made from plastic ^^

[jebem]

Nice photo of the Casio, Stefan.

1) Concerning the Casio missing key entries:
On my HP-300s+ I just took now the sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of sqrt of 11111 and after about 5 seconds the cal gave the result = 1.009138861.
Tried several times and never lost a single key entry.
Oh, and I'm not using the cell battery, just the solar panel for that.

2) On my HP-Prime, i did the same calculation as above (10 x sqrt of 11111, and the answer was immediate with the result = 1.00913886108.
This is really a beast of a calculator, no matter what others can tell. Buggy and picky maybe, but still an amazing machine.

3) Concerning where HP is sub-contracting the manufacturing of their calculators, let me add one more observation:
- Looking to the HP-300s+ PCB we see the reference "Juniper EA-631".
- Looking to the HP-Prime Logic PCB we see the reference "EA656 MB"
- Looking to the HP-Prime Diagnostic menu, we see EA656 in the title...
So this "EA" prefix in both HP calculators PCB is not a coincidence.
Now, both of them has a print in the back saying "Made in China".
And it seems that both were made by the same Chinese manufacturer.
And everybody says it is Kinpo Electronics, but there is no proof of that.

I have here a Casio Algebra FX 2.0 Plus and it says "Made in China" as well.
So Casio Japan doesn't make calculators anymore, they do the same as HP, just sub-contract one expert elsewhere to do the job.