itsy bitsy Unix

[Paul Koning]

>>>>> "Cameron" == Cameron Kaiser <spectre at floodgap.com> writes:

 Cameron> Does anyone know a true (not a homebrew hack) multitasking
 Cameron> environment that will run in 16K or less, preferably with
 Cameron> available source?

Does it have to be Unix?

There are some real-time OSs that fit in that sort of space.  You
might take a look at MicroC/OS -- which is open source and documented
in full in the book by its creator, Jean Labrosse.

The only drawback I noticed is that it has the somewhat peculiar
limitation that every task has a different priority, which is just the
opposite of what I want.

Another possibility would be to use FORTH.  That had (cooperative)
multitasking support for a very long time.

Come to think of it, cooperative multitasking is trivial, you can code
your own.  It looks like this:

     for {;;} { task1(); task2(); task3; /* etc */ }

and each task simply does stuff for a while, then returns when it has
nothing left to do or when it's time to give another task a shot at
the CPU.  That sort of system is very simple and very reliable.

    paul