For many years, high-performance processors were all based on multi-chip ECL CPUs. For example, from 1975 to 1991 Digital Equipment Corporation's highest performance processors were all based on multi-chip ECL CPUs -- from the (ECL) KL10 through the (ECL) VAX 9000 until the 1991 single-chip CMOS NVAX -- at the time, a single-chip ECL processor was expected to retake the lead.[30]