The R6000 is an ECL implementation of the MIPS architecture which was produced by Bipolar Integrated Technology. The R6000 miroprocessor did introduce the MIPS II instruction set. Its TLB and cache architecture are different from all other members of the MIPS family. The R6000 did not deliver the promised performance benefits, and although it saw some use in Control Data machines, it quickly disappeared from the mainstream market.
The R6000 is not supported by Linux/MIPS.