Epson 386SX - Manual (Page 188)

6. If you used the option card to add an external device to your
computer, did you use the proper cable to connect the
device to the option card connector on the back panel?
7. Did you perform the correct setup procedures for the
software you are using with the option card? If necessary, see
your software manual for instructions on running the
software setup procedure.
A-20 Troubleshooting