pycopy VS MCUDEV_DEVEBOX_H7XX_M

Oh, so you're interested to get 100 tomes of technical drawings for SpaceX? You may be out of luck with it, but with any open-source project you're in luck - source to answer all of your questions is right there ;-). https://github.com/pfalcon/pycopy in this case. There's also the testsuite which formally specifies everything Pycopy can do (coverage 97%): https://github.com/pfalcon/pycopy/tree/master/tests . Finally, the docs include the section on specific differences with CPython3.4: https://pycopy.readthedocs.io/en/latest/differences/index.html (but that's human-written, so definitely not complete). By the way, docs are 381 pages rendered as a PDF: https://pycopy.readthedocs.io/_/downloads/en/latest/pdf/ .

Really? Here's direct link to the closest subsection header: https://github.com/pfalcon/pycopy/#the-unix-version , and quoting it here for you:

Well, here it is: https://github.com/pfalcon/pycopy/blob/master/py/vm.c#L367

https://github.com/pfalcon/pycopy/tree/v3.5.0 (if you prefer to drop people into the code, since the release URL does not contain release notes)

that would probably be the one with the fastest MCU, which - depending on details, but generally spoken, is probably one out of the STM32H7xx series. There's MicroPython stuff for this: https://github.com/mcauser/MCUDEV_DEVEBOX_H7XX_M (random Google hit, but the page also mentions cheap boards you can source with that MCU). Note that the H7 is a ... bit of a step from the Cortex M4 MCU and certainly from the M3 and M0. Not sure if you ever plan to go further to the metal than just flashing Micropython and working with that... It's got a multitude of peripherals, too - don't expect Micropython abstractions for all of them. But then it's a M7 running at 480MHz (some STM32H7xx even 550 MHz) max, which probably matches the only requirement you mention.