The Custom (OEM) PCI 9054 board refers to a custom or specialized PCI (Peripheral Component Interconnect) expansion board based on the PLX PCI 9054 chip. The PLX PCI 9054 is a highly integrated, high-performance PCI-to-PCI bridge chip. This chip is used to connect two PCI buses or to create custom PCI systems that may require multiple PCI devices or bridges, typically used in embedded systems, industrial applications, or high-performance computing environments.

When referring to "Custom (OEM) PCI 9054 board," the term "OEM" typically indicates a customized version of the board that might have special configurations or modifications suited for a particular application or hardware setup. The driver for this board would allow Windows to communicate with the board via the PCI interface.