Configure the JetDirect card to act as an lpr print server (see the
  JetDirect documentation) and set up your SGI to use it as you would
  any remote lpr printer (see above). You may also want to set up a
  bridge to the 'lp' system; again, see above.

  Unless you have a very recent JetDirect card, you will not be able
  to use printers(1M) to set up the JetDirect as a remote lpr printer.
  You can either use the lpr software on the SGI (see above), or you
  can circumvent printers(1M) in one of the following ways:

  - Use printers(1M) to add a normal 'lpr' print server with the local
    printer name you'll want to use for the JetDirect printer.
  - Do '/usr/lib/lputil add /dev/null netface <local-printer-name>'.
  - Do '/usr/lib/lpadmin -p<local-printer-name> -mnetface -v /dev/null',
    and create by hand all of the directories and little files in
    /var/spool/lp.

  Each of the above will create an interface script in
  /var/spool/lp/interface/<local-printer-name>. Since you subverted the
  usual installation process, some of the settings in the script won't
  be right yet. Change HOSTNAME to the JetDirect's hostname, NETTYPE to
  "bsd" and (thanks to Ken Harris <kenh@netcom.com> for this one) SYNC
  to 0. If it's a Postscript printer, change TYPE to "PostScript" and
  CONVTYPE to "PostScriptFile".

  Bill Poitras <bill@ba.msi.com> adds: To print from a PC using SAMBA
  via your SGI, you can either modify the interface script so that
  specifying "-oraw" to lp (as suggested in the SAMBA documentation)
  will set CONVTYPE to nothing, or set up a second interface to the same
  printer and set its CONVTYPE to nothing permanently.

  If your JetDirect card is very old, it may not understand the lpr
  protocol at all. If it is very, very old, you may have to resort to
  sending the file over TCP port 9100 directly. If it is only very old,
  you may be able to upgrade the card to a version which does understand
  lpr. Upgrading the JetDirect is beyond the scope of this FAQ.