List of former IA-32 compatible processor manufacturers explained

As the 32-bit Intel Architecture became the dominant computing platform during the 1980s and 1990s, multiple companies have tried to build microprocessors that are compatible with that Intel instruction set architecture. Most of these companies were not successful in the mainstream computing market. So far, only AMD has had any market presence in the computing market for more than a couple of product generations. Cyrix was successful during the 386 and 486 generations of products but did not do well after the Pentium was introduced.

List of former IA-32 compatible microprocessor vendors:

Progressed into surviving companies

• Centaur Technology – originally subsidiary of IDT, later acquired by VIA Technologies, still producing compatible low-end devices for VIA
• Cyrix – acquired by National Semiconductor, later acquired by VIA Technologies, eventually shut down
• NexGen – bought by AMD to help develop the successful K6 device
• National Semiconductor – low-end 486 (designed in-house) never widely sold; first acquirer of Cyrix, later keeping only low-end IA-32 devices targeted for consumer System-on-a-chips, finally selling them to AMD

Product discontinued/transformed

• Harris Corporation – sold radiation-hardened versions of the 8086 and 80286; product line discontinued. Produced 20 MHz and 25 MHz 80286s (some motherboards were equipped with cache memory, which was unusual for 80286 processors).
• NEC – sold processors, such as NEC V20 and NEC V30, that were compatible with early Intel 16-bit architectures; product line transitioned to NEC-designed architectures.
• Siemens – sold versions of the 8086 and 80286; product line discontinued.
• V.M. Technology – developed VM860 (8086-compatible processor), VM8600SP (80286 compatibility with proprietary 32-bit extensions), and VM386SX+ (Intel 386SX pin compatible processor) for the Japanese market.^{[1] [2] [3] [4] [5]}

Left the market or closed

• Chips and Technologies – left market after failed 386 compatible chip failed to boot the Windows operating system
• IBM – Cyrix licensee and developer of Blue Lightning 486 line of processors, eventually left compatible chip market
• Rise Technology – after five years of working on the slow mP6 chip (released in 1998), the company closed a year later
• Texas Instruments and SGS-Thomson – licensees of Cyrix designs, eventually left compatible chip market
• Transmeta – transitioned to an intellectual property company in 2005
• United Microelectronics Corporation and Meridian Semiconductor – got out of market after a suit from Intel questioning the legality of copying Intel origin x86 microcode

Incomplete/unsuccessful projects

• Chromatic Research – media processor with x86 instruction set compatibility never completed
• Exponential Technology – x86-compatible microprocessor never completed^[6]
• S-MOS - 486-compatible project was canceled^[7]
• IIT Corp – 486-compatible project never completed^{[8] [9]}
• International Meta Systems – Pentium/PPro-class processors "Meta 6000", "Meta 6500", "Meta 7000/BiFrost" never completed^[10]
• Texas Instruments - internally developed Pentium class processor was canceled in 1996^[11]
• MemoryLogix – multi-threaded CPU core "MLX1" and SOC for PCs never completed^{[12] [13]}
• Metaflow Technologies – 486-class processor "CP100" never released^{[14] [15] [16]}
• Montalvo Systems – asymmetric multiprocessor never completed
• ULSI System Technology – never completed x86 SOC; company shut down after one of their employees was convicted for stealing Intel floating-point x87 design documents
• VLSI Technology - developed 386SX-based "Polar" SoC in collaboration with Intel^[17] - canceled due to low performance and lack of software support^[18]
• KAIST - developed but did not commercialize Intel-compatible processors HK386 and K486.^{[19] [20]}
• Henry Wong - developed a 2-way superscalar, out-of-order execution, 32-bit x86 processor soft core running at over 200 MHz on Altera Stratix IV FPGA.^[21]

See also

• List of x86 manufacturers

Notes and References

1. Web site: OASYS LX-4500. Japanese. Laptop using the VM867S CPU
2. Web site: N.. Komatsu. VM8600SP. Japanese.
3. Web site: CBR . KAY NISHI's VM TECHNOLOGY HAS 80386-COMPATIBLE CHIP… . May 4, 1988.
4. Microprocessor Report. Proliferation of 386/486-Compatible Microprocessors to Accelerate in ’92. January 22, 1992.
5. Microprocessor Report. Texas Instruments Extends 486 Line. November 15, 1993.
6. Microprocessor Report. EVSX Emerges from Exponential Ashes. December 29, 1997. https://web.archive.org/web/20220621213153/http://www.cecs.uci.edu/~papers/mpr/MPR/19971229/1117msb.pdf. June 21, 2022.
7. Microprocessor Report. PC Market Centers On Growing 486 Family. 8. 1. January 24, 1994. https://web.archive.org/web/20221219034527/http://www.cecs.uci.edu/~papers/mpr/MPR/ARTICLES/080101.pdf. December 19, 2022. Mentions S-MOS canceling their 486 class processor project along with IIT doing the same.
8. Microprocessor Report. PC Market Centers On Growing 486 Family. 8. 1. January 24, 1994. https://web.archive.org/web/20221219034527/http://www.cecs.uci.edu/~papers/mpr/MPR/ARTICLES/080101.pdf. December 19, 2022. Mentions IIT as developing a 486-class CPU for release in 1994.
9. Microprocessor Report. National Pushes 486 into Embedded Market. 9. 12. September 11, 1995. https://web.archive.org/web/20220621213153/http://www.cecs.uci.edu/~papers/mpr/MPR/ARTICLES/091201.pdf. June 21, 2022. Mentions NatSemi's licensing technology from IIT for its own NS486 processor.
10. Web site: International Meta Systems. Products. https://web.archive.org/web/19971014145742/http://www.imes.com/products.html. October 14, 1997. dead.
11. December 30, 1996. Intel Prepares MMX CPU Wave . Microprocessor Report. Mentions TI's 5th generation x86 processor project being canceled.
12. Peter Song, Web site: MLX1 - A Tiny Multithreaded 586 Core for Smart Mobile Devices . https://web.archive.org/web/20220120231030/https://dada.cs.washington.edu/smt/memoryLogix.pdf . January 20, 2022 . live.
13. Web site: The Linley Group . A Tale Of Two Companies . Linley Newsletter . May 27, 2008. https://web.archive.org/web/20230218092827/https://www.linleygroup.com/newsletters/newsletter_detail.php?num=4139. February 18, 2023.
14. Web site: Metaflow . https://web.archive.org/web/20010221042951/http://www.metaflow.com/html/cp100core.htm . CP100 High Performance 32-bit x86 Core . February 21, 2001 . dead.
15. Web site: . https://web.archive.org/web/20010225023318/http://www.eet.com/news/97/957news/drives.html . New processor drives STM buyout of Metaflow . 1997 . February 25, 2001 . dead.
16. Web site: Mark . Smotherman . Metaflow - Lightning/Thunder SPARC designs, x86 designs . February 2011 . https://web.archive.org/web/20221004095123/https://people.computing.clemson.edu/~mark/metaflow.html . October 4, 2022 . live.
17. [BYTE|Byte (magazine)]
18. Microprocessor Report. What’s Happened to the PDA Market?. 8. 12. September 12, 1994. https://web.archive.org/web/20221219034534/https://www.cecs.uci.edu/~papers/mpr/MPR/EDITOR/0812ed.pdf. December 19, 2022.
19. Kyung CM, etal. HK386: an x86-compatible 32-bit CISC microprocessor. January 1997. ASP-DAC 97. 10.1109/ASPDAC.1997.600351.
20. Joon-seo Yim et al, Verification Methodology of Compatible Microprocessors, 1997.
21. Web site: University of Toronto. Henry Ting-Hei Wong. A Superscalar Out-of-Order x86 Soft Processor for FPGA. 2017.