Ensure smooth data flow from either your serial or parallel port with an I/O Add-a-Port Adapter Cable from . Choose DB9-pin or DB25-pin male serial ports with a bracket or a DB25-pin female parallel port with a bracket. These adapter cables connect to the motherboard or I/O adapter via flat ribbon cabling. Connectors: Internal 26-pin IDS dual row to external DB25 Female. Compatible with most brands of motherboards and I/O cards. Application: Parallel.