PH> perfect example of something that falls into the class of systems
PH> that I call "soft" real-time.  Basically, you would really like
PH> real-time response but if you don't get it from time to time, nobody
PH> dies and nothing blows up.  

  OS/2 works fine for near real time control.  I have an application that
is text mode only and does some machine control-loop stuff.
However, the control loop is protected by an external watchdog
circuit because OS/2 has one obscure but potentially serious
problem with thread scheduling.  The PM Kernel is non-preemptible
between the WinBeginPaint and WinEndPaint calls.  Some PM programs
do all drawing during those calls, and even the highest priority time 
critical threads will not be scheduled.
--- Maximus/2 2.01wb