Epson Equity 386/33 PLUS Setup Manual page 27

Caution
Although the connectors and ports for the mouse and
keyboard are physically identical, they cannot be used
interchangeably. Be sure to plug the mouse connector into
the mouse port.
Once you have connected a mouse, you may need to add
commands to your MS-DOS CONFIG.SYS file (or equivalent) to
enable your computer to use a mouse. See your operating
system and mouse manuals for instructions.
Note
If you want to use a mouse or other pointing device
connected to an option card in your computer, disable the
built-in mouse connector by changing the setting of jumper
J2. See Chapter 4 of the User's Guide for instructions.
Setting Up Your System
1-14
mouse connector