HP QMS 1660 - Manual (Page 178)

Optional
Network
Interfaces
QMS 1660 Print System Reference 6-40
each time after walking around and before touching the printer con-
troller board again.
1 Turn off the printer, and then disconnect the power cord and
all interface cables (parallel, serial, and AppleTalk) from the
printer.
2 Access the printer controller board.
Use the instructions in the “Removing the Printer and Controller
Board Covers” section of this chapter.
3 Remove the two screws from one of the optional interface
plates on the back of the printer.
You can use either of the optional interface ports.
Save the two screws. (You’ll use them when you install the NIC.)
You can either save or discard the plate.