>"From 1975, with the introduction of the KL10, until 1991, when NVAX was released, the highest performance processors at DEC were built with ECL (emitter coupled logic) technology. Fast, hot, and not very dense, ECL was the technology of choice for high-end systems, not just at DEC, but at computer companies world-wide. Then, in the space of just a few short years, it became obsolete. In 1985, DEC's ECL systems were 7 times faster than the fastest CMOS systems. In 1992, they were no faster."
http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/logfam...
https://en.wikipedia.org/wiki/Category:Logic_families
http://simh.trailing-edge.com/semi/raven.html
>"From 1975, with the introduction of the KL10, until 1991, when NVAX was released, the highest performance processors at DEC were built with ECL (emitter coupled logic) technology. Fast, hot, and not very dense, ECL was the technology of choice for high-end systems, not just at DEC, but at computer companies world-wide. Then, in the space of just a few short years, it became obsolete. In 1985, DEC's ECL systems were 7 times faster than the fastest CMOS systems. In 1992, they were no faster."