Apple LaserWriter 12/640 PS - Manual (Page 126)

IMPORTANT If you select the On mode setting to turn on the EtherTalk,
NetWare, or TCP/IP interface, the change does not take effect until the printer
is turned off and back on again.
3 Click Set Port.
Resetting the communication settings
To restore the communication settings to the factory defaults:
1 Set the communication switch on the printer to the Reset (out) position.
2 Turn the printer off and back on again.
3 Set the communication switch on the printer to the Normal (in) position.
Configuring TCP/IP
You can specify the IP address of the printer. For information about
determining the printer’s IP address and setting up the printer on a TCP/IP
network, see Chapter 4.
1 Choose Configure TCP/IP from the Utilities menu.
2 Enter the IP address.
3 Enter the subnet mask.
You can specify a subnet mask only if the printer’s IP address is not 0.0.0.0.
Communication
switch
101 Setting Up the Printer for Windows, DOS, and NetWare Users