Elxsi (now Tata Elxsi) was a minicomputer manufacturing company established in the late 1970s along with a host of other competitors (Trilogy Systems, Sequent, Convex Computer) in Silicon Valley, USA. The Elxsi processor was an Emitter Coupled Logic (ECL) design that featured a 50 nanosecond clock, a 25 nanosecond backpanel bus, IEEE floating point arithmetic and a 64-bit architecture. It allowed multiple processors to communicate over a common bus called the Gigabus, believed to be the first company to do so. The operating system was a message based operating system called EMBOS. The Elxsi CPU was a microcoded design, allowing custom instructions to be coded into microcode. Elxsi was founded in 1979 by Joe Rizzi (previously a manager at Intersil) and Thampy Thomas (who would go on to found NexGen Microsystems). It is believed that Elxsi was the first startup founded by an Indian in Silicon Valley. Much of the architecture of the Elxsi machine was designed by former Stanford University professors Len Shar and Balasubrimanian Kumar. Another key contributor to the design was Harold (Mac) McFarland, who was also a key designer on the team that created the PDP-11. George Taylor (on the IEEE standard committee and a student of UC Berkeley Professor William Kahan) provided a key design for the IEEE floating point unit. Elxsi was bought out by Gene Amdahl with money that was left over from the Trilogy venture. Venture investors in Elxsi included Tata Group (India) and Arthur Rock. In 1989, however, Elxsi left the computer business because of the general shift away from the use of mainframes in the global computer industry and the advent of the personal computer. The Tata Group kept the name Tata Elxsi but it now belongs to the Tata group of companies.