The Intel 80286 is a 16-bit microprocessor that was introduced on February 1, 1982. It was the first 8086-based CPU with separate, non-multiplexed address and data buses and also the first with memory management and wide protection abilities. The 80286 used approximately 134,000 transistors in its original nMOS (HMOS) incarnation and, just like the contemporary 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088 processors.
The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus, and is notable as the processor used in the original IBM PC design.
The Intel 8088 microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range are unchanged, however. In fact, according to the Intel documentation, the 8086 and 8088 have the same execution unit (EU)—only the bus interface unit (BIU) is different. The 8088 was used in the original IBM PC and in IBM PC compatible clones.
The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor designed by Intel. The first pre-production samples of the 386 were released to select developers in 1985, while mass production commenced in 1986. The processor was a significant evolution in the x86 architecture, extending a long line of processors that stretched back to the Intel 8008. The 386 was the central processing unit (CPU) of many workstations and high-end personal computers of the time. The 386 began to fall out of public use starting with the release of the i486 processor in 1989, while in embedded systems the 386 remained in widespread use until Intel finally discontinued it in 2007.
The Intel 486, officially named i486 and also known as 80486, is a microprocessor. It is a higher-performance follow-up to the Intel 386. The i486 was introduced in 1989. It represents the fourth generation of binary compatible CPUs following the 8086 of 1978, the Intel 80286 of 1982, and 1985's i386.
The Intel 80186, also known as the iAPX 186, or just 186, is a microprocessor and microcontroller introduced in 1982. It was based on the Intel 8086 and, like it, had a 16-bit external data bus multiplexed with a 20-bit address bus.
A floating-point unit is a part of a computer system specially designed to carry out operations on floating-point numbers. Typical operations are addition, subtraction, multiplication, division, and square root. Some FPUs can also perform various transcendental functions such as exponential or trigonometric calculations, but the accuracy can be low, so some systems prefer to compute these functions in software.
The Intel i860 is a RISC microprocessor design introduced by Intel in 1989. It is one of Intel's first attempts at an entirely new, high-end instruction set architecture since the failed Intel iAPX 432 from the beginning of the 1980s. It was the world's first million-transistor chip. It was released with considerable fanfare, slightly obscuring the earlier Intel i960, which was successful in some niches of embedded systems. The i860 never achieved commercial success and the project was terminated in the mid-1990s.
Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas, as a specialist supplier of floating point units for 286 and 386 microprocessors. The company was founded by Tom Brightman and Jerry Rogers.
A coprocessor is a computer processor used to supplement the functions of the primary processor. Operations performed by the coprocessor may be floating-point arithmetic, graphics, signal processing, string processing, cryptography or I/O interfacing with peripheral devices. By offloading processor-intensive tasks from the main processor, coprocessors can accelerate system performance. Coprocessors allow a line of computers to be customized, so that customers who do not need the extra performance do not need to pay for it.
The Am386 CPU is a 100%-compatible clone of the Intel 80386 design released by AMD in March 1991. It sold millions of units, positioning AMD as a legitimate competitor to Intel, rather than being merely a second source for x86 CPUs.
The Intel 8087, announced in 1980, was the first floating-point coprocessor for the 8086 line of microprocessors. The purpose of the chip was to speed up floating-point arithmetic operations, such as addition, subtraction, multiplication, division, and square root. It also computes transcendental functions such as exponential, logarithmic or trigonometric calculations. The performance enhancements were from approximately 20% to over 500%, depending on the specific application. The 8087 could perform about 50,000 FLOPS using around 2.4 watts.
The Cyrix Cx486SLC is a x86 microprocessor that was developed by Cyrix. It was one of Cyrix's first CPU offerings, released after years of selling math coprocessors that competed with Intel's units and offered better performance at a comparable or lower price. It was announced in March of 1992, and released 2 months later in May, with a price of $119. It was priced competitively against the Intel 486SX, causing Intel to lower the price of their chip from $286 to $119 in just days.
The Cyrix Cx486DLC is an x86 desktop microprocessor developed by Cyrix. It was Cyrix's second CPU offering, released years after selling math coprocessors that competed with Intel's units and offered better performance at a comparable or lower price. It was released in June of 1992, with a price of $119 for computer manufacturers.
The Intel 80376, introduced January 16, 1989, was a variant of the Intel 80386SX intended for embedded systems. It differed from the 80386 in not supporting real mode and having no support for paging in the MMU. The 376 was available at 16 or 20 MHz clock rates.
x87 is a floating-point-related subset of the x86 architecture instruction set. It originated as an extension of the 8086 instruction set in the form of optional floating-point coprocessors that work in tandem with corresponding x86 CPUs. These microchips have names ending in "87". This is also known as the NPX. Like other extensions to the basic instruction set, x87 instructions are not strictly needed to construct working programs, but provide hardware and microcode implementations of common numerical tasks, allowing these tasks to be performed much faster than corresponding machine code routines can. The x87 instruction set includes instructions for basic floating-point operations such as addition, subtraction and comparison, but also for more complex numerical operations, such as the computation of the tangent function and its inverse, for example.
During the late 1980s, Intel sold two ISA expansion cards named Intel Inboard 386/AT and Intel Inboard 386/PC, which allowed users to upgrade an IBM AT or an IBM PC respectively. The boards allowed users to upgrade their machines' CPU to a 16 MHz 80386 processor. Both variants utilized a ribbon cable which plugged into the computer's original CPU socket on one end and into a socket on the Inboard card on the other end.
The Deskpro 386 is a line of desktop computers in Compaq's Deskpro range of IBM PC compatibles. The computers feature Intel's 32-bit 80386 microprocessor. Introduced in September 1986, the Deskpro 386 is the first implementation of the 80386 processor in a computer system for sale to the public. It also marks the first time that a major component of the IBM Personal Computer de facto standard was updated by a company other than IBM themselves—in this case, upgrading from the 80286 processor of the Personal Computer/AT.
The Intel 8231 and 8232 were early designs of floating-point maths coprocessors (FPUs), marketed for use with their i8080 line of primary CPUs. They were licensed versions of AMD's Am9511 and Am9512 FPUs, from 1977 and 1979, themselves claimed by AMD as the world's first single-chip FPU solutions.
