Intel 80286
Intel 80286
The Intel 80286, also known as the iAPX 286 and commonly referred to as the Intel 286, was a groundbreaking 16-bit microprocessor introduced by Intel on February 1, 1982. This processor marked a crucial evolution in computing technology by incorporating advanced features such as separate, non-multiplexed address and data buses, as well as sophisticated memory management and protection capabilities.
Architecture and Features
The 80286 represented a significant leap from its predecessor, the Intel 8086, as it featured a data size of 16 bits and an address width of 24 bits. This allowed it to address up to 16MB of memory, a substantial increase from the 1MB limit of the 8086. This capacity was particularly beneficial for operating systems such as Windows.
Utilizing approximately 134,000 transistors in its original nMOS (HMOS) implementation, the 80286 was compatible with most software developed for the Intel 8086 and Intel 8088 processors.
Clocking and Performance
Initially, the 80286 chips were designed to operate at a maximum clock rate of 5, 6, or 8 MHz, with later releases achieving speeds of up to 12.5 MHz. Variants produced by AMD and Harris Corporation reached speeds of 16 MHz, 20 MHz, and 25 MHz.
Protected Mode and Legacy
One of the hallmark features of the 80286 was its introduction of protected mode, which significantly enhanced the processor's capability by enabling more robust multitasking and memory protection. This mode was later extended with the release of the Intel 80386.
Industry Impact
The Intel 80286 played a pivotal role in the development of IBM Personal Computer AT, which implemented this processor, ushering in a new era of personal computing with its advanced features. Additionally, the processor was integral to the architecture of the Industry Standard Architecture bus systems.
Associated Technologies
The processor was also paired with the X87 math coprocessor series, enhancing its computational capabilities.
Legacy
The architectural advancements introduced by Intel 80286 paved the way for future developments in microprocessors, influencing the design and capabilities of subsequent chips such as the Intel 80386 and Intel 80486. The technologies and innovations fostered in the 80286 era continue to influence modern computing architectures.