Redirected from Intel 386
The processor was a significant evolution in a long line of processors that stretched back to the Intel 8008. The predecessor of the 80386 was the Intel 80286, a 16-bit processor. The 80386 brought a 32-bit architecture, which added a better (so-called flat) memory model that made the implementation of multiprocessing operating systems relatively easy. Before that time, personal computers based on Intel processors were almost exclusively driven by the DOS and CP/M systems that could run only one program at a time.
Intel later introduced the 80486, but neither it nor its successors under the Pentium name were as big a step as the 32-bit flat addressing made possible by the 80386. Most applications running on personal computers in 2003 will run on the older 80386, albeit very slowly; there are only a few instructions added to the main instruction set in later generations, and in most cases their usage is unnecessary. Building a program for the 80286 is much harder, and usually requires fundamental changes to the application.
Because of the high degree of compatibility, the whole range of processors compatible with the 80386 is often collectively termed the i386 architecture; the instruction set for the architecture is known as IA-32 or informally i386.
From a business perspective, the i386 was significant because it was the first significant microprocessor to be single-sourced -- i.e. it was available only from Intel Corp. Prior to this, the difficulty of making chips and the uncertainty of reliable supply required that any mass-market semiconductor be multi-sourced[?] -- made by two or more manufacturers, the second and subsequent ones manufacturing under license from the designer. Single-sourcing the i386 allowed Intel greater control over its development and substantially greater profits in later years.
See also List of Intel microprocessors
Search Encyclopedia
|
Featured Article
|