586

586, commonly associated with the Intel 80486 microprocessor family, is a 32-bit x86 architecture released by Intel in 1989 as the successor to the 80386. It brought several performance improvements, including an on-die level 1 cache and, in the DX variants, an integrated floating-point unit, enabling higher performance without requiring external co-processors for many applications. The 80486 used a pipelined design and supported 32-bit addressing and paging compatible with software written for the 386.

The 486 family included several variants: the 486DX, with an integrated FPU; the 486SX, a cost-reduced version without an internal FPU; late models included 486DX2, which used clock doubling to increase CPU frequency, and 486DX4 with an on-chip clock multiplier. There were also mobile and low-power versions such as the 486SL. The 486 family was manufactured by Intel and by other vendors, including AMD and Cyrix, as compatible products.

Impact and legacy: The 586/80486 improved overall PC performance through the early to mid-1990s, enabling more capable operating systems and applications and helping Windows-based software gain popularity. It remained a major workhorse until the Pentium era began in the mid-1990s, after which production declined. The 586 class established the shift to a 32-bit x86 market and influenced numerous successors in both consumer and professional computing, including embedded and enterprise systems.

Name usage: The term 586 is widely used to refer to the entire 80486 family and to the 586-class processors, denoting the generation between the 80386 and the Pentium. The 586 class holds historical significance in the evolution of the x86 line.