The Free On-line Dictionary of Computing (30 December 2018):

Psion Organiser

    A popular pocket computer from the UK Company
   Psion plc.  The organiser uses a graphical user interface
   with windows, menus, icons and dialog boxes.  There have
   been several versions so far: Series3a, Series3, HC, MC,
   OrgII.

   Usenet newsgroups: news:comp.sys.psion,
   news:comp.binaries.psion.

   (1995-03-03)