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The Intel's i486SL is the power-saving variant of the i486DX microprocessor. The SL was designed for use in mobile computers. It was produced between November 1992 and June 1993. Clock speeds available were 20, 25 and 33 MHz. The i486SL contained all features of the i486DX.
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, in the Silicon Valley. It is the world's second largest and second highest valued semiconductor chip manufacturer based on revenue after being overtaken by Samsung, and is the inventor of the x86 series of microprocessors, the processors found in most personal computers (PCs). Intel ranked No. 46 in the 2018 Fortune 500 list of the largest United States corporations by total revenue.
A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.
In addition, the System Management Mode (SMM) (the same mode introduced with i386SL) was included with this processor. The system management mode makes it possible to shut down the processor without losing data. To achieve this, the processor state is saved in an area of static RAM (SMRAM).
System Management Mode is an operating mode of x86 central processor units (CPUs) in which all normal execution, including the operating system, is suspended. An alternate software system which usually resides in the computer's firmware, or a hardware-assisted debugger, is then executed with high privileges.
In mid-1993, Intel incorporated the SMM feature and all other features in the 486SL in all its new 80486 processors and discontinued the SL series.
Refer to the respective section of the list of Intel microprocessors for technical details.
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 Intel 80386, also known as i386 or just 386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistors and were the CPU of many workstations and high-end personal computers of the time. As the original implementation of the 32-bit extension of the 80286 architecture, the 80386 instruction set, programming model, and binary encodings are still the common denominator for all 32-bit x86 processors, which is termed the i386-architecture, x86, or IA-32, depending on context.
The Intel 80486, also known as the i486 or 486, is a higher performance follow-up to the Intel 80386 microprocessor. The 80486 was introduced in 1989 and was the first tightly pipelined x86 design as well as the first x86 chip to use more than a million transistors, due to a large on-chip cache and an integrated floating-point unit. It represents a fourth generation of binary compatible CPUs since the original 8086 of 1978.
Intel's i486SX was a modified Intel 486DX microprocessor with its floating-point unit (FPU) disabled. It was intended as a lower-cost CPU for use in low-end systems. Computer manufacturers that used these processors include Packard Bell, Compaq, ZEOS and IBM.
The IntelDX4 is a clock-tripled i486 microprocessor with 16 KB L1 cache. Intel named it DX4 as a consequence of litigation with AMD over trademarks. The product was officially named the IntelDX4, but OEMs continued using the i486 naming convention.
The first Pentium microprocessor was introduced by Intel on March 22, 1993. Dubbed P5, its microarchitecture was the fifth generation for Intel, and the first superscalar IA-32 microarchitecture. As a direct extension of the 80486 architecture, it included dual integer pipelines, a faster floating-point unit, wider data bus, separate code and data caches and features for further reduced address calculation latency. In 1996, the Pentium with MMX Technology was introduced with the same basic microarchitecture complemented with an MMX instruction set, larger caches, and some other enhancements.
The Intel i486DX2, rumored as 80486DX2 is a CPU produced by Intel that was introduced in 1992. The i486DX2 was nearly identical to the i486DX, but it had additional clock multiplier circuitry. It was the first chip to use clock doubling, whereby the processor runs two internal logic clock cycles per external bus cycle. An i486 DX2 was thus significantly faster than an i486 DX at the same bus speed thanks to the 8K on-chip cache shadowing the slower clocked external bus.
The Intel i860 was a RISC microprocessor design introduced by Intel in 1989. It was one of Intel's first attempts at an entirely new, high-end instruction set architecture since the failed Intel iAPX 432 from the 1980s. It was released with considerable fanfare, slightly obscuring the earlier Intel i960, which was successful in some niches of embedded systems, and which many considered to be a better design. The i860 never achieved commercial success and the project was terminated in the mid-1990s.
The Am486 is a 80486-class family of computer processors that was produced by AMD in the 1990s. Intel beat AMD to market by nearly four years, but AMD priced its 40 MHz 486 at or below Intel's price for a 33 MHz chip, offering about 20% better performance for the same price.
The Am386 CPU is a 100%-compatible clone of the Intel 80386 design released by AMD in 1991. It sold millions of units, positioning AMD as a legitimate competitor to Intel, rather than being merely a second source for x86 CPUs.
In x86 computing, unreal mode, also big real mode, huge real mode, or flat real mode, is a variant of real mode, in which one or more segment descriptors has been loaded with non-standard values, like 32-bit limits allowing to access entire memory. Contrary to its name, it is not a separate addressing mode that the x86 processors can operate in. It is used in the 80286 and later x86 processors.
Socket 3 was a series of CPU Sockets for various x86 microprocessors. It was sometimes found alongside a secondary socket designed for a math coprocessor chip, in this case the 487. Socket 3 resulted from Intel's creation of lower voltage microprocessors. An upgrade to Socket 2, it rearranged the pin layout.
LOADALL is the common name for two different, undocumented machine instructions of Intel 80286 and Intel 80386 processors, which allow access to areas of the internal processor state that are normally outside of the IA-32 API scope, like descriptor cache registers. The LOADALL for 286 processors is encoded 0Fh 05h, while the LOADALL for 386 processors is 0Fh 07h.
Socket 1, originally called the "OverDrive" socket, was the second of a series of standard CPU sockets created by Intel into which various x86 microprocessors were inserted. It was an upgrade to Intel's first standard 168-pin pin grid array (PGA) socket and the first with an official designation. Socket 1 was intended as a 486 upgrade socket, and added one extra pin to prevent upgrade chips from being inserted incorrectly.
Socket 2 was one of the series of CPU sockets into which various x86 microprocessors were inserted. It was an updated Socket 1 with added support for Pentium OverDrive processors.
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 worked in tandem with corresponding x86 CPUs. These microchips had names ending in "87". This was 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.
In computing, Intel's Advanced Programmable Interrupt Controller (APIC) is a family of interrupt controllers. As its name suggests, the APIC is more advanced than Intel's 8259 Programmable Interrupt Controller (PIC), particularly enabling the construction of multiprocessor systems. It is one of several architectural designs intended to solve interrupt routing efficiency issues in multiprocessor computer systems.
The UMC Green CPU was an x86-compatible microprocessor produced by UMC, a Taiwanese semiconductor company, in the early- to mid-1990s. It was offered as an alternative to the Intel 80486 with which it was pin compatible, enabling it to be installed in most 80486 motherboards. All models had power management features intended to reduce electricity consumption.
The Cyrix Cx486 or Cyrix 486 was an x86-Compatible microprocessor designed by Cyrix to primarily compete with the Intel 486 with which it was software compatible, would operate in the same motherboards provided proper support by the BIOS was available and generally showed comparable performance. The chip also competed with parts from AMD and UMC.