Distributed System Architectures and concepts are increasingly being utilized and specified for ruggedized, real-time avionics, flight control, and ground based systems. Even though these systems have inherent advantages in the areas of fault tolerance, flexibility, extensibility, and adaptability they are characterized as being communications intensive. Realizing the positive attributes of distributed architectures requires the development/evolution of interconnect technology beyond what is currently available.This paper presents a description of the Sperry Defense Products Group - Computer Systems Division second generation High Speed Interconnect System (HSIS); developed during 1985 as part of a cooperative Internal Research and Development project. The HSIS is a 100 MBPS Token passing fiber optic bus that services up to 256 stations and utilizes an IEEE 802.4-like Token passing protocol. During 1986 the SAE AE-9B Linear Token Passing Bus protocol will be incorporated into the HSIS. The HSIS system architecture and design allows for technology insertion and supports a wide range of equipment types and capabilities by the incorporation of firmware personality modules.