486SL

The 486SL was a low-power variant of Intel's 80486 microprocessor, designed for portable computers. It was introduced in 1992, alongside the standard 486SX and 486DX processors. The "SL" designation stood for "Second Level," referring to its advanced power management capabilities, which were a significant step up from earlier mobile processors.

Key features of the 486SL included its ability to enter various low-power states, such as standby and sleep modes, to conserve battery life. It also incorporated System Management Mode (SMM), a dedicated mode for managing system resources and power consumption. This allowed for more sophisticated control over the CPU's clock speed, bus activity, and peripheral devices. The 486SL was available in clock speeds ranging from 20 MHz to 33 MHz and featured the same 32-bit architecture as other 486 processors, including an integrated floating-point unit and cache.

The 486SL was widely adopted in early laptops and notebooks, enabling longer battery life and more advanced features than previously possible. Its success paved the way for subsequent generations of Intel mobile processors, such as the Pentium and later mobile Core series, which continued to prioritize power efficiency and performance for portable computing. While not as well-known as its desktop counterparts, the 486SL played a crucial role in the evolution of the mobile computing landscape.