Lexmark C510 Setup Manual page 38

Parallel
Serial
A parallel port is included on base printer models.
A parallel port requires an IEEE-1284 compliant parallel cable such as
Lexmark part number 1329605 (3 m [10 ft]).
A serial port can be attached through the INA port on the printer
system board.
A serial port requires a compatible serial cable such as Lexmark part
number 1038693.
Attach cables
33