Mouse manager source code (for non Photon app)

Does anyone know if the source code for the Mouse manager shipped with QNX4
is available? I want to hook up two USB mice (through devu-mouse and Input)
but keep their input streams separate. The Mouse I/O manager actually works
quite nicely for this (using Input’s option for redirect events to
/dev/mousein) but Mouse merges the events and I can’t tell which mouse
generated the event (info that I need). (Note that this is for a non-Photon
app.)

Any ideas would be appreciated!

Thanks,
David Sheinberg
Brown University