Apple LaserWriter 12/640 PS - Manual (Page 27)

Adjusting communication settings
Though you can adjust many of the LaserWriter 12/640 PS printer’s
communication settings, the normal settings work for most environments.
To make sure the printer is set up to use the normal settings, check the
communication switch on the left side of the printer to make sure it’s in
the Normal (in) position. The settings are listed in Appendix D.
Why customize communication settings?
Though the standard communication settings work well for most
environments, you might want to customize communication settings to turn
off network interfaces you don’t need. For example, if you know the printer
will never receive a NetWare message over the network, you can turn off the
interface and stop the printer from sending out unnecessary NetWare packets.
Communication
switch
27 Setting Up the LaserWriter 12/640 PS