On June 8, 1978, with the release of the 16-bit Intel 8086 CPU, the x86 architecture was officially born. Nearly half a century later, this architecture is still used in most personal computers. Ironically, this chip and its x86 architecture—developed over 18 months—were initially just a transitional solution following delays in Intel's complex and entirely new 32-bit iAPX 432 project.

The Intel 8086 processor was designed by a team of four engineers and twelve layout engineers led by Stephen P. Morse. The project was reportedly intended to provide a practical and timely alternative to the upcoming 16-bit CPU designs from Motorola and Zilog. This legendary 8086 processor was merely a transitional solution, as Intel poured too much effort into the iAPX 432 project, which it had launched a year earlier, ultimately proving insufficient. Incidentally, the 432 processor was eventually released in 1981, but was considered too expensive, too complex, and too slow at the time.

The 8086 was the founding CPU of the x86 family and is hailed as Intel's first 16-bit processor. It benefited from partial backward compatibility with previous Intel 8-bit designs, such as the 8008, 8080, and 8085. Significant improvements over its predecessors included microcode for assembly language multiplication and division instructions.

A close examination of the hardware specifications reveals that the Intel 8086 contained approximately 20,000 transistors (29,277 in total, including ROM and PLA), manufactured using Intel's HMOS (High-Performance MOS) process, originally developed for high-speed static RAM products. The resulting 40-pin chip had an area of 33 square millimeters and a minimum feature size of 3.2 micrometers. Throughout its lifespan, the processor's clock frequency ranged from 5 to 10 MHz.

While the Intel 8086 laid the foundation for the x86 architecture, the subsequent 8088 design (1979) became the core of the first IBM PC (1981) and its legendary lineage.

The 8086's direct successors, such as the 80286, 80386, and 80486, spearheaded the Wintel alliance and established PC compatibles as the default choice for productivity, home computing, and computer gaming enthusiasts until they were superseded by the Pentium CPU (also x86) in the mid-1990s.

To celebrate the 40th anniversary of the original 8086 processor, Intel launched the Core i7-8086K 40th Anniversary Edition chip in 2018. It seems highly likely we'll see another commemorative product in 2028 to celebrate the 50th anniversary of the 8086 processor. So, what will the 50th anniversary celebration be? We hope it will reflect the fun and passion of personal computers.

The Story Behind the Rise of the x86 Processor

The dominance of x86 in personal computers and servers ultimately stems from IBM. Once again, the "Big Blue" demonstrated its ability to reverse a disadvantageous situation by "coming from behind."

Intel's first 16-bit microprocessor, the 8086 (iAPX 86), designed starting in early 1976 and released in mid-1978, marked the beginning of the most successful x86 processor series. Later, in 1979, the 8-bit data bus Intel 8088 was released, becoming one of the low-cost simplifications of the 8086, and was used in the first-generation IBM PC processor, gaining widespread recognition. IBM's choice made x86 the most widespread "language" (instruction set architecture) in the personal computer and server field, and also destined x86 instruction set compatible processors to dominate the computer industry "outside of mobile devices" today, establishing the future of "Wintel" (the combination of Microsoft Windows and Intel) as a technology giant.

IBM needs a completely new way of thinking to enter the personal computer market

The reasons why IBM chose the x86 instruction set compatible processor, which even AMD found utterly illogical, have long been the subject of much debate. Before the 1980s, IBM was a supplier of mainframe commercial computers, symbolized by its System/360 mainframe successor compatible products from 1964. However, in the microcomputer field (starting with DEC's PDP-8 released in 1964), it lagged far behind its competitors. This emerging market had already reached $15 billion in sales in 1979, and was projected to grow at an annual rate of over 40% in the 1980s.

Nearly half a century ago, in 1973, IBM created the engineering prototype of the "world's first personal computer," SCAMP (Special Computer APL Machine Portable), simulating the IBM 1130 minicomputer to run the APL/1130 programming language. This evolved into the IBM 5100, released in September 1975. Weighing 25 kilograms, it housed a complete computer with ample read-only memory (ROM), dynamic access memory (RAM), a 5-inch CRT monitor, a tape drive, and a keyboard, all packed into a briefcase. What would be considered a behemoth today was a huge breakthrough for "portable computers" at the time.

However, like the later IBM RT/PC (RISC Technology Personal Computer, January 1986), the IBM 5100 was priced at a hefty $20,000, and its target market wasn't truly focused on "personal computers." If IBM wanted to enter this market, it would need a more competitive price and a faster product development timeline. However, IBM's corporate culture and systems were accustomed to a slow and methodical approach of "doing things from scratch," with new product development often taking 4-5 years. This slow pace was simply not effective in urging others to act quickly. As one industry analyst famously said at the time: "Telling IBM to launch a personal computer is like teaching an elephant to do a twerking dance." In other words, IBM had to adopt entirely new thinking and methods, or it would have no chance at all.

Personal computers are built using existing imported standard products

IBM PCs broke with its traditional "doing everything in-house" approach, adopting a completely open-standard approach from the ground up, using existing components and open specifications throughout, both hardware and software, to minimize development time and achieve the fastest time to market.

IBM had discussed the possibility of collaborating with Panasonic to manufacture personal computers and even considered acquiring Atari to become a manufacturer of future microcomputers. However, it ultimately decided to create a completely new department, abandoning all traditional IBM practices. The new computers would "introduce external expertise," featuring an open architecture and fully utilizing open hardware and software. The goal was to complete a prototype within 30 days, finish product development and launch within a year, and project sales of 220,000 units over three years, exceeding the total number of IBM computers already installed.

Market research was also a major driving force behind this change. They discovered that dealers were very interested in selling IBM PCs but insisted on using "standardized, not IBM-exclusive" components so that retailers could repair them themselves, rather than requiring customers to send faulty machines back to IBM customer service.

IBM considered Texas Instruments (TI) TMS9900, Motorola 68000, and Intel 8088. Although Motorola 68000 was undoubtedly the best option in retrospect and in the eyes of IBM engineers at the time, and was even used in the later IBM System 9000 laboratory computer, the 8088 was chosen based on cost considerations, IBM System/23 Datamaster's familiarity with the Intel 8085, processor manufacturing licensing (in exchange for Intel Bubble Memory patents), and the availability of the CP/M-86 operating system (which was quickly replaced by Microsoft DOS). This decision cast a shadow of the x86 instruction set over the computer industry.

The dominant position of x86 instruction set compatible processors in today's computer industry originated from IBM's historic decision when it created personal computers. Even IBM and Intel at the time probably couldn't have imagined that it would have such a profound impact on later generations.

IBM rapidly developed products and pioneered the blue ocean of personal computers

IBM launched its personal computer project in 1980, designing the motherboard in just 44 days, building a prototype in four months, demonstrating it internally in January 1981, and completing the entire design and preparing for mass production in April 1981. Except for system assembly, which was handled by IBM factories, all components were supplied by third parties. 

No functional components were designed by IBM; for example, the monitor was an off-the-shelf product from IBM Japan, and the printer came from Epson Japan. Therefore, IBM did not obtain any patents for the first-generation personal computer. After a year of development, the IBM PC finally debuted on August 12, 1981, starting at $1,565, far lower than the $10,000 price tag of the Datamaster, which had been touted as "IBM's cheapest computer" just two weeks earlier.

The IBM PC was a huge success upon its release, with sales exceeding IBM's expectations by "eight times," at one point reaching 40,000 units shipped per month. By 1983, IBM had sold over 750,000 personal computers, prompting DEC, IBM's competitor in the market, to sell only 69,000 units. By 1984, IBM's personal computer revenue reached $4 billion, more than double that of Apple during the same period. Thanks to its open specifications, less than a year after the IBM PC's debut, in June 1982, compatible models from other brands appeared on the market, thus ushering in the great era of personal computers and providing Taiwan's electronics industry with an opportunity for rapid development.

It is worth mentioning that the "high-quality Model F capacitive keyboard" played a crucial role in the success of the IBM PC. Originally developed for the System/23 Datamaster, the Model F keyboard's number of keys, reliability, and ergonomics far surpassed all other home computer keyboards on the market at the time. It was not only widely recognized as one of the main selling points of the IBM PC but was even considered "the best keyboard for any microcomputer."

The Model F keyboard, with its clear tactile feedback, robust durability, and average key failure interval of over 100 million keystrokes, was one of the main reasons why IBM PCs were so popular when they were first launched. To this day, countless "keyboard squirrels" still cherish a rare and exquisite copy. In 2016, a community of enthusiasts even funded the "reproduction" of this keyboard, which is older than most people, attracting more than 25,000 people to participate.

x86 instruction set compatible processors gradually dominate the computer industry

In short, the Intel Pentium, the first superscalar x86 processor launched on March 22, 1993, established x86 processors' place in the high-performance arena. On November 1, 1995, the Intel Pentium Pro, combining decoupled superscalar architecture, speculative execution, and improved microprocessor scalability, opened the door to servers and workstations for x86 processors.

The release of Microsoft Windows 95 operating system and Office 95 suite on July 14 of the same year, with its improved graphical user interface, significantly lowered the barrier to entry and ignited a new growth boom in the personal computer market, achieving a record of 100 million units shipped annually in 1998, a record that wasn't broken until 2021 with 350 million units shipped.

x86 instruction set compatible processors possess the capital to dominate today's cloud data centers, stemming from their massive foundation in the personal computer market. Beyond Apple's PowerMac, the RISC camp's repeated attempts to enter the personal computer market in the 1990s all ended in failure. Apple's initial shift from PowerPC to x86 in the early 21st century further solidified Intel's (and AMD's) dominance.

However, the true influence of x86 extends beyond personal computers and servers. Embedded systems, commonly found in industrial computers and IoT applications, are the true origin of x86 and Intel's core competency. "The original 8086 started out as an embedded processor" remains deeply ingrained in Intel's DNA. The 8086 was initially created for embedded processors, as were the earlier 8080, 8008, and 4004. Even today, there are more x86 processors used in embedded applications than all personal computers combined.

In recent years, AMD has become increasingly aggressive in this market, rapidly catching up. Its third-quarter financial report showed embedded product revenue reaching $1.3 billion (exceeding the $1 billion of general PC user revenue), a 15.5-fold increase compared to the same period last year (1,549%, though the author is skeptical, as it may be due to different computing benchmarks). This demonstrates the significant effort invested and the high level of market demand.

Two contemporary computer architecture masters (or "RISC professors") have commented in their works that "only the people who created the x86 instruction set will like it." We also have ample reason to believe that if another, more logical instruction set had dominated the world, the current computer industry would be far more diverse. However, it is extremely regrettable that history never offers "what ifs."

Source: Compiled from tomshardware

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