It seems to me rather that developing all the low-level stuffs (file systems
abstractions, drivers, serial comm etc..) are somewhat limited in Java.
Everyone seems to say that Java is geared more for enterprise and such but
I like Java but still those above can't be done! any ideas fellow
usenetters ?

Basically anything platform or hardware specific you need to write the
code it C/C++ and glue it in with JNI.  You can write several versions
of it, and have Java Web Start plug in the correct one for any given
platform.

See http://mindprod.com/jgloss/jni.html

Java is not design to support "low level" programming. It is designed
to allow abstracted interaction with the parent platform. While it
might be possible to write drivers in pure Java, its unlikely to see
whole Operation Systems written in Java, simply because Java itself
"requires" an OS to run on.

Although, I could see a specialty JVM implementation that doesn't
require a parent OS, I'm not aware of any of the top of my head.

Actually, I think Java is rather good at certain 'low level' tasks.
It's threading model is easy to learn and it has support for byte
arrays, What more do you need?

Your state machine lives in one Thread and you listen to the comm port
on another. Nice !

Rgds
Duncan