%N pgupdt %F $MIR/src/pgupdt.f
%D Update display
%B
      SUBROUTINE PGUPDT

 Update the graphics display: flush any pending commands to the
 output device. This routine empties the buffer created by PGBBUF,
 but it does not alter the PGBBUF/PGEBUF counter. The routine should
 be called when it is essential that the display be completely up to
 date (before interaction with the user, for example) but it is not
 known if output is being buffered.

 Arguments: none
