> MK> Someone who knows why?  And is it going to be fixed in time
 > MK> for Merlin?  Or maybe it isn't fixable?
 >
 > Try "DIR C:\ /S > NUL" and you will not see any
jerkiness in the mouse.
 > What is happening is that the mouse movements are being processed by the
 > operating system, but the screen cannot be updated quickly enough to show
 > it.  Updating the mouse cursor is, I believe, handled by a separare
 > thread in PM.

Yes, I know.  So if one could change the priority for the mouse-thread then
the jerkiness would go away?  And why isn't the mouse set to time critical
in the first place?

And when the scrolling is going on the other programs gets no or close to
no cpu at all.  I made a PM-program that has at thread that updates a
counter and it stops completly when the scrolling is occuring.  But when I
changed the update thread in my program to timecritical it got cpu OK. So
there is something else going on here.  Is the scrolling set to timeritical
for DOS and OS/2-windows?

And it's just those DOS and OS/2-windows that gets this effect.  I don't
have the same problem when scrolling for example an E.EXE window.

Maybe something with the VIO-subsystem?

Many questions and guesses now :-)

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