Epson EL 486UC - Manual (Page 19)

Connecting the Computer
Use the illustration below to locate the ports on the back of
your system as you connect the keyboard, monitor, printer, and
other devices.
Connecting a Keyboard
To connect a keyboard, hold the cable connector so the arrow
on the connector faces up. Insert it into the port marked K/B.
Connecting a Mouse
Your system came with a serial mouse that connects to either of
the computer’s built-in serial ports. To connect the mouse,
insert the connector into one of the ports marked COMl and
COM2.
Setting Up Your System 1-3