On a sunny day (Mon, 04 Jan 2021 14:03:31 -0500) it happened Dennis Lee Bieber
 wrote in :

>On Mon, 4 Jan 2021 17:15:45 -0000 (UTC), Martin Gregorie
> declaimed the following:
>
>
>>
>>Out of pure curiosity: have you any idea how much work it would be to
>>convert a fully debugged BS2 BASIC program into a running SPIN program?
>
>        Probably a lot. One concept with the Propeller is that one assigns
>cores to do what would have been an interrupt in other chips (instead of
>having an interrupt, that core is in a polling loop). Also using cores for
>dedicated I/O protocols. The GPIOs are shared by all cogs.
>....

If I read this it makes me wonder why not go FPGA, learn Verilog for example.
Then you can basically create your own processor, cores, and it is widely used
and
proven technology, also with a wide experimental open source user base:
 https://opencores.org/projects
make your own processor, elect one!:
 https://opencores.org/projects?expanded=Processor

FPGA boards are cheap on ebay these days.
It also enhances your value on the IT market.
It helps to have hardware design experience.
IIRC there also is an FPGA HAT for Raspberry.

Design your own processor, with your own instruction set...
Sky is the limit, as is speed it seems.

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