the MIPS instruction set
/ mips /
MIPS is a classic RISC instruction set architecture, for decades the standard teaching ISA in computer-architecture courses and textbooks, and the close cousin of RISC-V. If RISC-V is the recipe this domain cooks from, MIPS is the older recipe from the same tradition — so similar that almost everything you learn about one transfers directly to the other. It came out of Stanford in the 1980s and powered everything from workstations to game consoles to routers.
Its design is RISC to the core: simple, fixed 32-bit instructions, a load-store architecture where only loads and stores reach memory, and 32 general-purpose registers (with register 0 hardwired to zero, just like RISC-V's x0). Its three instruction formats — R-type for register arithmetic, I-type for immediates and loads/stores, J-type for jumps — are the direct ancestors of the formats you see in RISC-V. The family resemblance is so strong that a MIPS program and a RISC-V program for the same task look like dialects of one language: 'add', 'lw', 'sw', 'beq' mean essentially the same things.
MIPS matters here mainly as a learning bridge and a piece of honest history. It shows that the clean RISC ideas in RISC-V are not new or unproven — they were worked out and shipped in real, commercially successful hardware long ago. The honest caveat is that MIPS, unlike RISC-V, was a proprietary architecture controlled by a company and licensed for fees, which is exactly the openness gap that RISC-V was created to close. Knowing MIPS makes RISC-V instantly familiar, and vice versa.
A MIPS add is 'add $t0, $t1, $t2' and a load is 'lw $t0, 0($t1)'; the RISC-V equivalents are 'add x5, x6, x7' and 'lw x5, 0(x6)'. Different register names and syntax, the same underlying RISC idea.
MIPS and RISC-V are dialects of the same RISC language — learn one and the other comes free.
MIPS proved the RISC approach in real, shipping hardware decades ago — but it was proprietary and licensed. RISC-V's main departure is not the design, which is similar, but that the ISA itself is open and free.