The PMC-8681 is a four-port UART (Universal Asynchronous Receiver/Transmitter) PCI Mezzanine Card (PMC). The PMC-8681 uses the OX16PCI954 that provides quad serial ports and supports a PCI interface for four 16C950 high performance UART channels.
The UART ports use a flat cable to DB-9 connector. All UART ports are fully software compatible with 16C550-type devices. The PMC-8681 is compatible with single board computers that support PMC slots.