Oki 390 - Manual (Page 14)

ML390/391 Turbo Printer Handbook 7
Pin assignments for both the parallel and the serial interfaces are listed in
appendix E.
You must supply the cable for connecting your printer to your computer.
1. Make sure both printer and computer
are OFF.
2. Locate interface port on back of printer.
3. Plug parallel interface cable into port
and secure it in place with wire loops.
Interface port
Wire
loops