Epson Expression 636 User Manual page 19

2. Connect the 25-pin end of the cable to the computer; then
tighten the screws on the sides of the connector.
3. Plug the 36-pin end of the cable into the scanner's parallel
interface connector. Then squeeze the wire clips together
until they lock in place on both sides.
Note:
If your parallel cable has a ground wire, attack it to the scanner's
ground terminal.
Setting Up the Scanner 1-7