Intel 80386
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Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...

Intel
386, originally released as 80386 and later renamed i386, is a 32-bit
microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...

microprocessor
introduced in 1985. The first versions had 275,000 transistorsmit.edu—The Future of FPGAs
(Cornell) October 11, 2012
and were the
CPU
CPU
of many
workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

workstation
s and high-end
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s of the time. As the original implementation of the
32-bit In computer architecture In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. A ...
extension of the
80286 The Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is on ...

80286
architecture, the i386 instruction set, programming model, and binary encodings are still the common denominator for all 32-bit
x86
x86
processors, which is termed the ''i386-architecture'', ''x86'', or ''
IA-32 IA-32 (short for "Intel Architecture, 32-bit", commonly called i386) is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the Intel 80386, 80386 microprocessor in 1985. IA-32 is the first inc ...
'', depending on context. The 32-bit i386 can correctly execute most code intended for the earlier 16-bit processors such as 8086 and 80286 that were ubiquitous in early PCs. Over the years, successively newer implementations of the same architecture have become several hundreds of times faster than the original 80386 (and thousands of times faster than the 8086). The 20 MHz version operates 4-5 MIPS. It also performs between 8,000 to 9,000 Dhrystones per second. A 33 MHz 80386 was reportedly measured to operate at about 11.4 MIPS. Development of i386 technology began in 1982 under the internal name of P3. The
tape-out In electronics design, electronics and photonics design, tape-out or tapeout is the final result of the integrated circuit design, design process for integrated circuits or printed circuit boards before they are sent for manufacturing. The tapeout ...
of the 80386 development was finalized on July 1985. The 80386 was introduced as pre-production samples for software development
workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

workstation
s in October 1985. Manufacturing of the chips in significant quantities commenced in June 1986, Introduced October 1985, production chip in June 1986. The first 80386 computers were released around October 1986. along with the first plug-in device that allowed existing 80286-based computers to be upgraded to the 386, the Translator 386 by
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.
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s for 80386-based computer systems were cumbersome and expensive at first, but manufacturing was justified upon the 80386's mainstream adoption. The first
personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or techn ...
to make use of the 80386 was the Deskpro 386, designed and manufactured by
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and marked the first time a fundamental component in the
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de facto standard was updated by a company other than . In May 2006, Intel announced that i386 production would stop at the end of September 2007. Although it had long been obsolete as a
personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or techn ...
CPU, Intel and others had continued making the chip for
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s. Such systems using an i386 or one of many derivatives are common in
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aerospace
technology and electronic musical instruments, among others. Some mobile phones also used (later fully static
CMOS Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss", ) is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOS ...
variants of) the i386 processor, such as BlackBerry 950 and
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.
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Linux
continued to support i386 processors until December 11, 2012; when the kernel cut 386-specific instructions in version 3.8.


Architecture

The processor was a significant evolution in the architecture, and extended a long line of processors that stretched back to the
Intel 8008 The Intel 8008 ("''eight-thousand-eight''" or "''eighty-oh-eight''") is an early byte-oriented microprocessor designed by Computer Terminal Corporation (CTC), implemented and manufactured by Intel, and introduced in April 1972. It is an 8-bit CP ...

Intel 8008
. The predecessor of the 80386 was the
Intel 80286 The Intel 80286 (also marketed as the iAPX 286 and often called Intel 286) is a 16-bit computing, 16-bit microprocessor that was introduced on February 1, 1982. It was the first 8086-based CPU with separate, non-multiplexed address bus, address ...

Intel 80286
, a
16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range (computer programming), range of integer values that can be stored in 16 bits depends on the Integer (computer ...
processor with a segment-based memory management and protection system. The 80386 added a three-stage instruction pipeline which it brings up to total of 6-stage instruction pipeline, extended the architecture from
16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range (computer programming), range of integer values that can be stored in 16 bits depends on the Integer (computer ...
s to
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s, and added an on-chip
memory management unit A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit having all computer memory, memory references passed through itself, primarily performing the translation of virtual address, virtua ...
. This
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translation unit made it much easier to implement operating systems that used
virtual memory In computing, virtual memory, or virtual storage is a Memory management (operating systems), memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "cr ...
. It also offered support for register debugging. The 80386 featured three operating modes: real mode, protected mode and virtual mode. The
protected mode In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing unit A central processing unit (CPU), also called a central processor, main processor or just Processor (com ...
, which debuted in the 286, was extended to allow the 386 to address up to 4 GB of memory. With the addition of segmented addressing system, it can expand up to 64 terabytes of virtual memory. The all new virtual 8086 mode (or ''VM86'') made it possible to run one or more
real mode Real mode, also called real address mode, is an operating mode of all x86-compatible Central processing unit, CPUs. The mode gets its name from the fact that addresses in real mode always correspond to real locations in memory. Real mode is char ...
programs in a protected environment, although some programs were not compatible. It features scaled indexing and 64-bit barrel shifter. The ability for a 386 to be set up to act like it had a flat memory model in protected mode despite the fact that it uses a segmented memory model in all modes was arguably the most important feature change for the x86 processor family until
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released
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in 2003. Several new instructions have been added to 386: BSF, BSR, BT, BTS, BTR, BTC, CDQ, CWDE, LFS, LGS, LSS, MOVSX, MOVZX, SETcc, SHLD, SHRD. Two new segment registers have been added (FS and GS) for general-purpose programs, single Machine Status Word of 286 grew into eight
control register A control register is a processor register which changes or controls the general behavior of a Central processing unit, CPU or other digital device. Common tasks performed by control registers include interrupt control, switching the addressing ...
s CR0–CR7. Debug registers DR0–DR7 were added for hardware breakpoints. New forms of MOV instruction are used to access them. Chief architect in the development of the 80386 was John H. Crawford. He was responsible for extending the 80286 architecture and instruction set to 32-bit, and then led the microprogram development for the 80386 chip. The
i486 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 ...
and P5
Pentium Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel. The Pentium (original), original Pentium processor from which the brand took its name was first released on March 22, 1993. After that, th ...
line of processors were descendants of the i386 design.


Data types

The following data types are directly supported and thus implemented by one or more i386 machine instructions; these data types are briefly described here.: * ''Bit'' ( boolean value), ''bit field'' (group of up to 32 bits) and ''bit string'' (up to 4 Gbit in length). * ''8-bit integer (byte)'', either signed (range −128..127) or unsigned (range 0..255). * ''16-bit integer'', either signed (range −32,768..32,767) or unsigned (range 0..65,535). * ''32-bit integer'', either signed (range −231..231−1) or unsigned (range 0..232−1). * ''Offset'', a 16- or 32-bit displacement referring to a memory location (using any addressing mode). * ''Pointer'', a 16-bit selector together with a 16- or 32-bit offset. * ''Character'' (8-bit character code). * ''String'', a sequence of 8-, 16- or 32-bit words (up to 4 Gbit in length). *'' BCD'', decimal digits (0..9) represented by unpacked bytes. *''Packed BCD'', two BCD digits in one byte (range 0..99).


Example code

The following i386 assembly source code is for a subroutine named _strtolower that copies a null-terminated ASCIIZ character string from one location to another, converting all alphabetic characters to lower case. The string is copied one byte (8-bit character) at a time. The example code uses the EBP (base pointer) register to establish a call frame, an area on the stack that contains all of the parameters and local variables for the execution of the subroutine. This kind of
calling convention In computer science, a calling convention is an Programming language implementation, implementation-level (low-level) scheme for how subroutines or functions receive Parameter (computer programming), parameters from their caller and how they Retu ...
supports reentrant and recursive code and has been used by Algol-like languages since the late 1950s. A flat memory model is assumed, specifically, that the DS and ES segments address the same region of memory.


Chip variants


80386SX

In 1988, Intel introduced the 80386SX, most often referred to as the 386SX, a cut-down version of the 80386 with a 16-bit data bus, mainly intended for lower-cost PCs aimed at the home, educational, and small-business markets, while the 386DX remained the high-end variant used in workstations, servers, and other demanding tasks. The CPU remained fully 32-bit internally, but the 16-bit bus was intended to simplify circuit-board layout and reduce total cost. The 16-bit bus simplified designs but hampered performance. Only 24 pins were connected to the address bus, therefore limiting addressing to 16  MB, but this was not a critical constraint at the time. Performance differences were due not only to differing data-bus widths, but also due to performance-enhancing cache memories often employed on boards using the original chip. The original 80386 was subsequently renamed i386DX to avoid confusion. However, Intel subsequently used the "DX" suffix to refer to the
floating-point In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an Integer (computer science), integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. ...
capability of the i486DX. The 387SX was an 80387 part that was compatible with the 386SX (i.e. with a 16-bit databus). The 386SX was packaged in a surface-mount QFP and sometimes offered in a socket to allow for an upgrade.


80386SL

The 80386SL was introduced as a power-efficient version for
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s. The processor offered several power-management options (e.g. SMM), as well as different "sleep" modes to conserve battery power. It also contained support for an external
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of 16 to 64 KB. The extra functions and circuit implementation techniques caused this variant to have over 3 times as many
transistor file:MOSFET Structure.png, upright=1.4, Metal-oxide-semiconductor field-effect transistor (MOSFET), showing Metal gate, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A ...
s as the i386DX. The i386SL was first available at 20 MHz clock speed, with the 25 MHz model later added.


Business importance

The first PC based on the Intel 80386 was the
Compaq Deskpro 386 The Deskpro 386 was a line of desktop computers in Compaq's Compaq Deskpro, Deskpro range of IBM PC compatibles. The computers featured Intel's 32-bit i386, 80386 microprocessor. Introduced in September 1986, the Deskpro 386 was the first implement ...
. By extending the 16/24-bit
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standard into a natively 32-bit computing environment,
Compaq Compaq Computer Corporation (sometimes abbreviated to CQ prior to a 2007 rebranding) was an American information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced ...
became the first company to design and manufacture such a major technical hardware advance on the PC platform. IBM was offered use of the 80386, but had manufacturing rights for the earlier
80286 The Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is on ...
. IBM therefore chose to rely on that processor for a couple more years. The early success of the Compaq Deskpro 386 played an important role in legitimizing the PC "clone" industry and in de-emphasizing IBM's role within it. Prior to the 386, the difficulty of manufacturing microchips and the uncertainty of reliable supply made it desirable that any mass-market semiconductor be multi-sourced, that is, made by two or more manufacturers, the second and subsequent companies manufacturing under license from the originating company. The 386 was for ''a time'' (4.7 years) only available from Intel, since Andy Grove, Intel's CEO at the time, made the decision not to encourage other manufacturers to produce the processor as
second source In the electronics industry, a second source is a company that is licensed to manufacture and sell components originally designed by another company (the first source). It is common for engineers and purchasers to avoid components that are only av ...
s. This decision was ultimately crucial to Intel's success in the market. The 386 was the first significant microprocessor to be single-sourced. Single-sourcing the 386 allowed Intel greater control over its development and substantially greater profits in later years.
AMD Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California Santa Clara (; Spanish for " Saint Clare") is a city in Santa Clara County, California. The city's population was 12 ...
introduced its compatible Am386 processor in March 1991 after overcoming legal obstacles, thus ending Intel's 4.7-year monopoly on 386-compatible processors. From 1991 IBM also manufactured 386 chips under license for use only in IBM PCs and boards.


Compatibles

* The
AMD Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California Santa Clara (; Spanish for " Saint Clare") is a city in Santa Clara County, California. The city's population was 12 ...
Am386SX and Am386DX were almost exact clones of the i386SX and i386DX. Legal disputes caused production delays for several years, but AMD's 40 MHz part eventually became very popular with computer enthusiasts as a low-cost and low-power alternative to the 25 MHz 486SX. The power draw was further reduced in the "notebook models" (Am386 DXL/SXL/DXLV/SXLV), which could operate with 3.3 V and were implemented in fully static
CMOS Complementary metal–oxide–semiconductor (CMOS, pronounced "sea-moss", ) is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOS ...
circuitry. *
Chips and Technologies Chips and Technologies (C&T), founded in Milpitas, California in December 1984 by Gordon A. Campbell and Dado Banatao, was an early fabless semiconductor company. Its first product, announced September 1985, was a four chip Enhanced Graphics Ad ...
Super386 38600SX and 38600DX were developed using
reverse engineering Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...
. They sold poorly, due to some technical errors and incompatibilities, as well as their late appearance on the market. They were therefore short-lived products. *
Cyrix Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas, as a specialist supplier of floating point units for Intel 80286, 286 and Intel 80386, 386 microprocessors. The company was founded by Tom Brightman ...
Cx486SLC/ Cx486DLC could be (simplistically) described as a kind of 386/486 hybrid chip that included a small amount of on-chip cache. It was popular among computer enthusiasts but did poorly with OEMs. The Cyrix Cx486SLC and Cyrix Cx486DLC processors were pin-compatible with i386SX and i386DX respectively. These processors were also manufactured and sold by
Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...
. * 386SLC and 486SLC/DLC were variants of Intel's design which contained a large amount of on-chip cache (8 KB, and later 16 KB). The agreement with Intel limited their use to IBM's own line of computers and upgrade boards only, so they were not available on the open market.


Early problems

Intel originally intended for the 80386 to debut at 16 MHz. However, due to poor yields, it was instead introduced at 12.5 MHz. Early in production, Intel discovered a marginal circuit that could cause a system to return incorrect results from 32-bit multiply operations. Not all of the processors already manufactured were affected, so Intel tested its inventory. Processors that were found to be bug-free were marked with a double
sigma Sigma (; uppercase Σ, lowercase Letter case is the distinction between the Letter (alphabet), letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowercase (or more formally ''minuscule'') in the wr ...
(ΣΣ), and affected processors were marked "16 BIT S/W ONLY". These latter processors were sold as good parts, since at the time 32-bit capability was not relevant for most users. Such chips are now extremely rare and became collectible. The i387 math coprocessor was not ready in time for the introduction of the 80386, and so many of the early 80386 motherboards instead provided a socket and hardware logic to make use of an 80287. In this configuration the FPU operated asynchronously to the CPU, usually with a clock rate of 10 MHz. The original Compaq Deskpro 386 is an example of such design. However, this was an annoyance to those who depended on floating-point performance, as the performance advantages of the 80387 over the 80287 were significant. Image:Intel A80386-12.jpg , A very early 80386 at 12 MHz (A80386-12), before the 32-bit multiply bug was found Image:Intel A80386-16 16 bit SW Only.jpg , An A80386-16 marked "16 BIT S/W ONLY" with the multiply bug Image:Intel A80386-16 ΣΣ.jpg , A bug-free A80386-16 marked "ΣΣ"


Pin-compatible upgrades

Intel later offered a modified version of its 486DX in i386 packaging, branded as the Intel RapidCAD. This provided an upgrade path for users with i386-compatible hardware. The upgrade was a pair of chips that replaced both the i386 and i387. Since the 486DX design contained an FPU, the chip that replaced the i386 contained the floating-point functionality, and the chip that replaced the i387 served very little purpose. However, the latter chip was necessary in order to provide the FERR signal to the mainboard and appear to function as a normal floating-point unit. Third parties offered a wide range of upgrades, for both SX and DX systems. The most popular ones were based on the Cyrix 486DLC/SLC core, which typically offered a substantial speed improvement due to its more efficient instruction pipeline and internal L1 SRAM cache. The cache was usually 1 KB, or sometimes 8 KB in the TI variant. Some of these upgrade chips (such as the 486DRx2/SRx2) were marketed by Cyrix themselves, but they were more commonly found in kits offered by upgrade specialists such as Kingston, Evergreen and Improve-It Technologies. Some of the fastest CPU upgrade modules featured the IBM SLC/DLC family (notable for its 16 KB L1 cache), or even the Intel 486 itself. Many 386 upgrade kits were advertised as being simple drop-in replacements, but often required complicated software to control the cache or clock doubling. Part of the problem was that on most 386 motherboards, the
A20 line The A20, or address line 20, is one of the electrical lines that make up the system bus of an x86-based computer system. The A20 line in particular is used to transmit the 21st bit on the address bus. A microprocessor typically has a number of ...
was controlled entirely by the motherboard with the CPU being unaware, which caused problems on CPUs with internal caches. Overall, it was very difficult to configure upgrades to produce the results advertised on the packaging, and upgrades were often not very stable or not fully compatible.


Models and variants


Early 5 V models


i386DX

Original version, released in October 1985. The 16 MHz version was available for 299 
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in quantities of 100. The 20 MHz version was avaiable for USD $599 in quantities of 100. * Capable of working with 16- or 32-bit external busses * Package: PGA-132 which was available in sampling for fourth quarter of 1985 or PQFP-132 * Process: First types
CHMOS CHMOS refers to one of a series of Intel CMOS processes developed from their Depletion-load NMOS logic#The HMOS processes, HMOS process. (H stands for high-density). It was first developed in 1981. CHMOS was used in the Intel 80C51BH, a new vers ...
III, 1.5 µm, later CHMOS IV, 1 µm * Die size: 104 mm2 (ca. 10 mm × 10 mm) in CHMOS III and 39 mm2 (6 mm × 6.5 mm) in CHMOS IV. * Transistor count: 275,000 * Specified max clock: 12 MHz (early models), later 16, 20, 25 and 33 MHz


M80386

The military version was made using the CHMOS III process technology. It was made to withstand 105
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(Si) or greater. It was available for USD $945 each in quantities of 100.


i386SX


RapidCAD

A specially packaged Intel 486DX and a dummy
floating-point unit In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an Integer (computer science), integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. ...
(FPU) designed as pin-compatible replacements for an i386 processor and i387 FPU.


Versions for embedded systems


80376

This was an embedded version of the 80386SX which did not support real mode and paging in the MMU.


i386EX, i386EXTB and i386EXTC

System and power management and built in peripheral and support functions: Two 82C59A interrupt controllers; Timer, Counter (3 channels); Asynchronous SIO (2 channels); Synchronous SIO (1 channel); Watchdog timer (Hardware/Software); PIO. Usable with 80387SX or i387SL FPUs. * Data/address bus: 16 / 26 bits * Package: PQFP-132, SQFP-144 and PGA-168 * Process: CHMOS V, 0.8 µm * Specified max clock: ** i386EX: 16 MHz @2.7–3.3 volts or 20 MHz @3.0–3.6 volts or 25 MHz @4.5–5.5 volts ** i386EXTB: 20 MHz @2.7–3.6 volts or 25 MHz @3.0–3.6 volts ** i386EXTC: 25 MHz @4.5–5.5 volts or 33 MHz @4.5–5.5 volts


i386CXSA and i386SXSA (or i386SXTA)

Transparent power management mode, integrated MMU and TTL compatible inputs (only 386SXSA). Usable with i387SX or i387SL FPUs. * Data/address bus: 16 / 26 bits (24 bits for i386SXSA) * Package: BQFP-100 * Voltage: 4.5–5.5 volts (25 and 33 MHz); 4.75–5.25 volts (40 MHz) * Process: CHMOS V, 0.8 µm * Specified max clock: 25, 33, 40 MHz


i386CXSB

Transparent power management mode and integrated MMU. Usable with i387SX or i387SL FPUs. * Data/address bus: 16 / 26 bits * Package: BQFP-100 * Voltage: 3.0 volts (16 MHz) or 3.3 volts (25 MHz) * Process: CHMOS V, 0.8 µm * Specified max clock: 16, 25 MHz


Obsolescence

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was the only entry in the
Windows 9x Windows 9x is a generic term referring to a series of Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft Microsoft Corporation is an American multi ...
series to officially support the 386, requiring at least a 386DX, though a 486 or better was recommended;
Windows 98 Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. The second operating system in the 9x line, it is the successor to Windows 95, and was Software rel ...
requires a 486DX or higher. In the
Windows NT Windows NT is a Proprietary software, proprietary Graphical user interface, graphical operating system produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-use ...
family, Windows NT 3.51 was the last version with 386 support. Debian GNU/Linux removed 386 support with the release of 3.1 (''Sarge'') in 2005. Citing the maintenance burden around SMP primitives, the
Linux kernel The Linux kernel is a Free and open-source software, free and open-source, Monolithic kernel, monolithic, Modular programming, modular, Computer multitasking, multitasking, Unix-like operating system kernel (operating system), kernel. It was ori ...
developers cut support from the development codebase in December 2012, later released as kernel version 3.8. Among the
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s,
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's 5.x releases were the last to support the 386; support for the 386SX was cut with release 5.2, while the remaining 386 support was removed with the 6.0 release in 2005.
OpenBSD OpenBSD is a security-focused operating system, security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking N ...
removed 386 support with version 4.2 (2007),
DragonFly BSD DragonFly BSD is a Free and open-source software, free and open-source Unix-like operating system fork (software), forked from FreeBSD 4.8. Matthew Dillon, an Amiga developer in the late 1980s and early 1990s and FreeBSD developer between 1994 ...
with release 1.12 (2008), and
NetBSD NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to be ac ...
with the 5.0 release (2009).


See also

*
List of Intel microprocessors This generational list of Intel processors attempts to present all of Intel Corporation, Intel's microprocessor, processors from the pioneering 4-bit computing, 4-bit Intel 4004, 4004 (1971) to the present high-end offerings. Concise technical da ...


Notes and references


External links


Intel 80386 Programmer's Reference Manual 1986

Intel 80386 processor family

Intel 231746-001 Introduction to the 80386 Apr86 (April 1986) and Including the 80386 Data Sheet Intel 231630-002 80386 HIGH PERFORMANCE 32-BIT MICROPROCESSOR WITH INTEGRATED MEMORY MANAGEMENT—Data Sheet for 80386-12 and 80386-16

1988 Intel Microprocessors and Peripheral Handbook Volume 1 Microprocessor including 80386 HIGH PERFORMANCE 32-BIT CHMOS MICROPROCESSOR WITH INTEGRATED MEMORY MANAGEMENT October 1987 Order Number: 231630-004

1989 Intel Microprocessor and Peripheral Handbook Vol 1 Microprocessor including 386™ MICROPROCESSOR HIGH PERFORMANCE 32-BIT CHMOS MICROPROCESSOR WITH INTEGRATED MEMORY MANAGEMENT November 1988 Order Number: 231630-005

Detailed list of early 80386 steppings (revisions)
{{Authority control Computer-related introductions in 1985
386 __NOTOC__ Year 386 (Roman numerals, CCCLXXXVI) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Honorius and Euodius (or, less frequ ...
32-bit microprocessors