Epson LT - 286e - Manual (Page 109)

Switch 4-This switch defines the primary display.
Set this switch to ON if the primary display is color.
Set this switch to OFF if the primary display is monochrome.
Switch 5--This switch is reserved and must always be ON.
Switch 6-This switch tells the computer whether the serial
port on the side of the computer is configured as a primary port
or a secondary port.
Set this switch to ON if you want the serial port to be
recognized as the primary serial port ($3F8-$3FF).
Set this switch to OFF if you want the serial port to be
recognized as the secondary serial port ($2F8-$2FF).
Switch 7-This switch enables or disables the serial port on the
side of the computer. If you install an option card that offers
serial ports, you may need to disable the internal serial port if it
conflicts with the port on the option card.
Set this switch to ON to enable the serial port.
Set this switch to OFF to disable the serial port.
Switch 8--This switch tells the computer whether the parallel
port on the side of the computer is configured as a primary port
or a secondary port.
Set this switch to ON if you want the parallel port to be
recognized as the primary parallel port ($378-$37F).
Set this switch to OFF if you want the parallel port to be
recognized as the secondary parallel port ($278-$27F).
Switch 9--This switch enables or disables the parallel port on
the side of the computer.
Set this switch to ON to enable the parallel port.
Set this switch to OFF to disable the parallel port.
Switch IO-This switch is not used and must be set to ON.
A-8 DIP Switches and Slide Switches