The 171 CBU 78090, 171 CBU 98090 and 171 CBU 98091 processors include an I/O-Bus port. The port is located in the same relative position on the processor as on other Momentum processors. When you replace an existing processor with a 171 CBU 78090, 171 CBU 98090 or 171 CBU 98091 processor, you can reconnect to I/O-Bus devices without having to modify the existing I/O-Bus cabling.