IO Crest 2 Port DB9 Serial and 1 Port DB25 Parallel PCIe 1.0 x1 Expansion Card | eBay
Amazon.com: GODSHARK PCIe Serial Expansion Card, 2 Port PCI Express 1.0 x 1 to Industrial DB9 COM RS232 Converter Adapter Controller for Desktop PC (Will Also Work on PCI-E x4, x8, x16