DuckCorp Dico

Found one definition

1.                 From The Free On-line Dictionary of Computing (19 January 2023):
                   
   
   
                   
                     
   Physical Sequential
   QSAM
   Queued Sequential Access Method
      <file format> (PS, QSAM, Queued Sequential Access Method) The
      simplest data set on an IBM mainframe.  Sequential files
      can only be read or written from the beginning: they do not
      support random access.
      [Why "Queued"?]
      (2003-12-05)