[ChuckMcM]

One of the cool things about "personal computers", when they were not synonymous with "IBM PC" or x86 box, was that you had total control over every bit and byte that went into them. Sometimes you had to use switches to manually set memory contents, sometimes there was a hard coded 'boot loader' which would do that for you. The coolest demo I think I've seen in this space was an FPGA computer design where the first download into the FPGA made it a serial device that could write memory, and then you erased that and loaded a computer which would then read that memory and execute it.

I believe that one of the reasons the Arduino has the appeal it does is because you can know everything there is to know about the program it is running. That is a lot of fun for a technologist.

It would be fun to have this blog posting written from within a debugger. I always found it intriguing to 'debug a program into existence' as it were.

[kunai]

It's kind of the same deal now with the Raspberry Pi, except for the fact that it uses RISC and not x86. It's a great tinkering platform.

Now, if only somebody would make a ring-0 OS for ARM... Now THAT would be fun.

[pjmlp]

You mean like Active Oberon?

http://www.ocp.inf.ethz.ch/wiki/

Not sure how workable this version is, but you can check on the forums,

ftp://ftp.lrz.de/transfer/BlueBottle-A2/ARMRelease.zip

You just need to enjoy using Pascal syntax languages for system programming.

[nitrogen]

There is FreeRTOS (http://www.freertos.org/).