Serg,

> I know pretty much zip about the internals, but would it be 
> possible to have
> a blocking call that looks for a pen down, instead of 
> checking an event
> queue (which is what I assume is happening) in an event loop.

That's certainly possible but it has a serious downside: If the VM blocks,
then *everything* blocks. Meaning that while you're waiting in a blocking
call for some input no Smalltalk process will be running. This might be
acceptible in some cases but I doubt that it's a good general idea.

  A.