MIPS R4000 Microprocessor
Following the R3000 microprocessor, in 1992 the R4000 was the first microprocessor released by the reformed MIPS Technologies Inc. semiconductor design firm. Similar to Sun Microsystems, MIPS designs chips, but does not manufacture them. Instead, MIPS licensed or sub-contracted their R4000 line of wafers to custom semiconductor manufacturers including NEC, Toshiba, LSI Logic, and Integrated Device Technologies (IDT). Although not apparent from the numerical identification, the R4000 was preceded by the R6000 processor, which was released in 1991.