When Intel released the 80386 in 1985, it introduced the first 32-bit x86 processor. This was a foundational shift, expanding registers and address space while maintaining backward compatibility for the massive DOS software library. It set the stage for Windows 3.0, early Linux, and the PC's architectural dominance for decades.

Beyond its architecture, the 386 delivered a major arithmetic performance leap. Multiplication and division, previously slow on the 8086, were accelerated using dedicated hardware that processes at one bit per cycle. The chip reused its main ALU and microcode to handle 8, 16, and 32-bit operations, balancing speed with silicon efficiency.

The 386 used an add-and-shift multiplication algorithm, not the Booth method. It employed internal registers MULTMP, TMPB, and SIGMA, with an early-out optimization for zero or all-one multiplier bits. For division, it employed a standard non-restoring algorithm. These microcode-driven routines, detailed in the programmer's manual, showcase the engineering trade-offs of the era.