X86
x86 is an instruction set architecture (ISA) designed for the Intel 8086 microprocessor, an 16-bit chip which was first produced in 1978[1]
The 8088, a direct descendant of this chip (an 8-bit data bus was added to the 8086) is notable for being the chip used in the very first IBM PC, which was first sold beginning in 1983. The 8086 would later come to be called the "186" in Intel's long line of processors.[1]
Remarkably, around this time Intel and Microsoft jointly made a decision to maintain backward compatibility in both hardware and software, with the result that all subsequent "Intel" processor chips could always execute the original x86 instructions. This agreement would later have a profound impact on the Personal Computer industry, and came to be known as the "WinTel" agreement.
Furthermore, this joint decision meant that any program which ran on the original Microsoft DOS operating system, whose hardware platform was always guaranteed to be x86, continued to execute successfully on later versions of Microsoft operating systems.
This decision to maintain backward compatibility of hardware and software laid the groundwork for the subsequent success of the x86 family of microprocessors, and the IBM compatible PCs which contain them.
References
- ↑ 1.0 1.1 ["http://www.intel.com/museum/online/hist_micro/hof/index.htm" "Intel Museum: The Microprocessor Hall of Fame"].