Epson 4500 - Manual (Page 85)

Setting the DIP Switches
Your printer has two sets of DIP (Dual Inline Package) switches located
under a small cover above the control panel. By changing the settings
of these switches, you can control various printer features, such as the
character set and page length. The new settings become effective when
the printer is turned on, reset, or initialized.
DIP switch settings are shown in the DIP switch tables starting on page
3-7. Descriptions of all the DIP switch functions begin on page 3-9.
Changing a DIP Switch Setting
To change a DIP switch setting, first turn off the printer. Then open the
DIP switch cover and use a pointed object, such as a pen, to change the
DIP switch settings. A DIP switch is on when it is up, and off when it is
down.
The new DIP switch settings take effect when the printer is turned on.
3-6 Using the Printer