30 Years Ago: Intel 386, 486 Chips Set the Stage for Windows Dominance

eWEEK 30: Intel’s 386 chip brought 32-bit computing to the x86 architecture while the 486 chip brought improved performance, enabling Windows to handle heftier enterprise applications.

In December 2012, Linux developer Ingo Molnar sent Linus Torvalds a note, suggesting that he drop support of Intel’s iconic i386 processor from Linux.

The problem, Molnar, a Red Hat employee, explained, was that the work involved in continuing support of the processor far outweighed any benefits. The “complexity has plagued us with extra work whenever we wanted to change SMP primitives, for years,” Molnar wrote.

“Unfortunately there's a nostalgic cost: your old original 386 DX33 system from early 1991 won't be able to boot modern Linux kernels anymore,” he told Torvalds. “Sniff.”

Torvalds reportedly shot back, “I’m not sentimental. Good riddance.”

There might not be a lot of nostalgia for the i386 or its follow-on, the i486, but when they hit the market in 1985 and 1989, respectively, they represented a significant step forward for Intel and its x86 architecture at a time when RISC (Reduced Instruction Set Computing) architecture was dominant.

The chips brought the processing power and memory capacities that would help Microsoft’s Windows operating system to run some of the larger data center applications. They also helped set the stage for the client/server computing model, added fuel to the worldwide adoption of PCs and enabled Intel to grow into the world’s largest chip maker. Torvalds would develop Linux on this platform in 1991.

The i386—or the 386, as it later become known—was the first Intel chip to offer 32-bit computing capabilities, a step up from the 16-bit 286 predecessor. Intel wouldn’t boost the capabilities of its x86 CPUs to 64 bit until the 2000s (following on the heels of Advanced Micro Devices’ move to produce its 64-bit x64 processors). The 486 would be the first x86-based CPU to contain a million transistors.

At the time, there were IBM-compatible PCs that were powered by Intel’s x86 chips and running Windows. But RISC was the top architecture, found in the massive servers and workstations of the time. However, those chips were too powerful and expensive for most desktop systems, leaving the field wide open for an architecture like the x86.

The 386 was the third generation of Intel’s processors, and the one that made the big difference in PCs. It would take awhile, but Windows would come to love the 386 and 486, particularly as Microsoft added greater sophistication to its graphical user interface (GUI) along with support for multitasking.

“When the [386] chips first came out, the conventional wisdom was that nobody would need that much processing power for a desktop computer,” Nathan Brookwood, principal analyst for Insight 64, told eWEEK. “So the first systems to use it were servers.”

The 386, which eventually hit speeds up to 33MHz, brought with it a range of capabilities and features that weren’t on the previous 286. Not only was it 32-bit, but it also could support operating systems that used virtual memory. It offered hardware debugging and operated in three modes, including one that made it backward-compatible with 8086 and 8088, a protected mode that enabled it to run like the 286 and the virtual mode for multitasking.

The chip also used a memory segment architecture that was similar to what had been used in earlier processor models, but Intel increased the size of the memory segments to 4GB, a significant jump up.

It took Microsoft several years to embrace the capabilities of the 386 in Windows, but the features in the chip provided the processing power to support Windows 3.0, 3.1 and 95.