Compaq Deskpro 386

Compaq Deskpro 386

Company type	Product line
Industry	Computer hardware
Founded	September 1986 (1986-09)
Founder	Gary Stimac (project leader)
Headquarters	Houston , United States
Products	Desktop computers featuring Intel 80386 microprocessor

The Deskpro 386 represents a series of desktop computers within Compaq's Deskpro lineup of IBM PC compatible machines. Launched in September 1986, it was the pioneering personal computer to incorporate Intel's 32-bit 80386 microprocessor. This introduction marked a significant advancement in the core technology of the IBM Personal Computer de facto standard by a manufacturer other than IBM, upgrading from the 80286 CPU used in the Personal Computer/AT.

Under the leadership of Gary Stimac, a team of 250 engineers developed the Deskpro 386, which garnered widespread praise and found extensive use across corporate and scientific sectors. Compaq continued to enhance this product line as Intel released newer iterations of the 386 processor.

Specifications

The Deskpro 386 retains the same ISA bus architecture as the IBM Personal Computer/AT, but substitutes its 16-bit Intel 80286 CPU with Intel’s 32-bit 80386. The initial offerings—the Deskpro 386 Model 40, Model 70, and Model 130—primarily vary in hard disk size and quantity of ISA expansion slots. Each model is equipped with a minimum of 1 MB RAM and operates on a 16-MHz Intel 80386 processor. The Model 40 features a 40 MB ESDI hard drive alongside six ISA slots (three supporting 8-bit, three supporting 16-bit). Models 70 and 130 are outfitted with larger ESDI drives of 70 MB and 130 MB respectively, each providing five expansion slots (three for 8-bit, two for 16-bit). The chassis design follows earlier Deskpro versions, offering four half-height 5.25-inch drive bays plus a standard 1.2-MB floppy disk drive. While Models 40 and 70 utilize half-height hard drives, Model 130 employs a full-height unit.

Rather than integrating memory directly on the motherboard, Compaq positioned RAM on a daughtercard that connects via a proprietary 32-bit bus slot on the mainboard to facilitate faster data throughput. Initial daughtercards come with 1 MB RAM, expandable up to 2 MB by populating additional sockets. This daughtercard also includes a slot for an auxiliary "piggyback" card that can add another 4 MB RAM, upgradeable to 8 MB. Consequently, the maximum initial RAM capacity achievable through this configuration was 10 MB. Additional memory expansion is possible through ISA cards, although these are constrained by the ISA’s slower, 16-bit data interface.

Development

Although the Intel 80286 processor predated IBM's release of the PC AT, companies such as Compaq waited until IBM established the standard before launching AT-compatible systems in 1985, including the Deskpro 286. In January 1986, Compaq engineer Hugh Barnes informed CEO Rod Canion that IBM showed no immediate plans to adopt the newer 80386 CPU. Aiming to pioneer PC advancements, Canion reached out to Intel president Andy Grove with an offer to develop hardware based on the 80386.

Gary Stimac, Compaq's vice president of engineering and fifth employee hired by the company, spearheaded the Deskpro 386 project and expanded his team to around 250 engineers by mid-1986. This initiative involved close cooperation among Compaq, Intel, and Microsoft, all bound by a three-way non-disclosure agreement. After Intel revealed the initial block diagram for the 80386 architecture in March 1985, development commenced. By June that year, Intel had supplied comprehensive specifications that enabled Compaq to strategize product lines incorporating the new processor.

Compaq recognized that being first to market with the Deskpro 386 carried risks if IBM introduced incompatible products later. CEO Canion had anticipated since at least 1982 that IBM could not revert to proprietary systems without harming its own position. The company concluded that IBM’s DOS standard had become more influential than IBM itself. Microsoft was engaged to ensure compatibility with existing MS-DOS software and to explore operating systems better suited for true 32-bit processing. At launch time, Microsoft's most advanced OS was Xenix System V/286—available as an option—with a native 32-bit version for the 386 expected in early 1987. Microsoft CEO Bill Gates fully supported the Deskpro 386 initiative, recognizing it as a turning point away from IBM's dominance toward innovation driven by companies like Compaq and Intel.

Early prototypes of the Deskpro 386 operated with a CPU clock speed of 12 MHz paired with a bus clock running at half that frequency (6 MHz). By product release, improvements in manufacturing yields allowed use of faster processors running at 16 MHz along with an increased bus clock speed of 8 MHz. Regarding memory technology, Stimac’s team assessed four options—static-column DRAM, page mode DRAM, asynchronous DRAM, and cache-backed DRAM—and selected static-column DRAM as offering the best balance between performance and cost. Although initially considering SCSI drives for storage, they abandoned this approach due to poor performance over the ISA bus and instead opted for ESDI drives equipped with onboard controllers to achieve satisfactory mass storage speeds.

Release

In a move that caught the media off guard, Canion, Grove, and Intel's Gordon Moore unveiled the Deskpro 386 on September 9, 1986, during an event held in New York City. The launch was attended by notable figures including Gates and Compaq chairman Ben Rosen.

The Deskpro 386 was the pioneer in bringing the 80386 processor to the commercial market. Pricing for the lineup started at US$6,499 for the Model 40, $7,299 for the Model 70, and $8,799 for the Model 130. The Wall Street Journal observed that these prices fell "in the lower range" of what industry experts had anticipated. The media spotlighted Compaq’s role as a key innovator in maintaining compatibility while upgrading a core part of the IBM Personal Computer architecture, with InfoWorld headlining: "Compaq Introduces 386 PC, Challenges IBM to Match It". Canion issued a challenge to IBM, warning they had six months to respond with their own 386-based system or risk losing market dominance while also addressing compatibility issues. IBM eventually launched their inaugural 386 PC—the Personal System/2 Model 80—in July 1987, nearly a year after Compaq's announcement.

As reported by The New York Times, the Deskpro 386 cemented Compaq’s position as a leader within the personal computer sector and dealt a significant blow to IBM’s reputation and revenue streams.

Sales

Although widespread adoption of 386-based PCs did not surge until 1989, Compaq managed to sell 25,000 Deskpro 386 units by February 1987—just half a year post-launch. Dun's Business Month characterized this achievement as "extraordinary acceptance" for a $6,500 machine built around a novel processor without native operating system support. The Deskpro 386 quickly gained traction among business executives and financial professionals who demanded superior processing capabilities. Early forecasts from Yankee Group and Dataquest estimated sales between 35,000 and 70,000 units for 1987; however, Compaq surpassed expectations by selling 90,000 units in the second quarter alone.

While IBM responded to sluggish sales by lowering prices on their Model 80, Compaq’s Deskpro 386 was reported to be "selling like crazy," with its higher profit margins motivating retailers to dedicate more shelf space. By late 1987, Compaq had exhausted its Deskpro 386 inventory and was contending with backorders extending into mid-1988. That year, despite the older Deskpro 286 outselling it in total units, the Deskpro 386 generated the highest revenue among Compaq’s offerings. Following the introduction of Extended Industry Standard Architecture by Compaq and other clone manufacturers in 1988, Compaq commanded a 28% share of the market for 386-based systems compared to IBM’s 16%.

Reception

The technology press responded positively to the Deskpro 386. Stephen Satchell of InfoWorld described it as the "hottest IBM PC compatible currently available," emphasizing that it operated at twice the speed of any AT-style computer tested and was priced reasonably given its performance. Bill Howard and William Wong from PC Magazine commended its robust build quality and exceptional compatibility with PC standards, labeling it a "screamer" that rendered most AT models sluggish in comparison. Tom Hill of The Ottawa Citizen praised its enhanced processing speed and rapid hard drive performance, calling it a high-quality personal computer that ran quietly while delivering unmatched speed. Looking back in 2006, PC World ranked the Deskpro 386 as the second greatest personal computer ever released, trailing only behind the original Apple II.

Later iterations

Compaq persisted in enhancing the Deskpro 386 series by incorporating updated versions of the Intel 386 processor. In 1987, they launched the Deskpro 386/20, equipped with a 20-MHz 386 CPU, marking it as one of the earliest microcomputers utilizing this processor variant. At that time, InfoWorld recognized it as the fastest IBM PC compatible available.

The following year, 1988, saw the introduction of two models: the Deskpro 386/25 and the Deskpro 386S. The Deskpro 386/25 featured a 25-MHz 386 processor, while the Deskpro 386S was built around Intel's more affordable 386SX chip, which employed a 16-bit data bus rather than a full 32-bit one. Notably, the Deskpro 386S was the inaugural PC to incorporate the 386SX processor. Meanwhile, the Deskpro 386/25 surpassed all previously evaluated systems in performance, establishing a new benchmark for 386-based computers despite its premium price tag of US$10,000. The Deskpro 386S officially debuted on June 20, 1988.

Subsequent variants such as the Deskpro 386n and Deskpro 386s/20n came in more compact "trimline" chassis and utilized 386SX CPUs tailored for local-area network applications. These models offered fewer expansion slots but were positioned at a considerably lower price point.

See also

• Apricot VX FT, recognized as the first computer system to ship with the i486 processor, which succeeded the 386
• Influence of the IBM PC on the personal computer market