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The Rise of Microsoft, Part 5: The Empire of DOS

The Empire of DOS

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💻 The Rise of Microsoft — a 20-part series. See all parts »  |  « Part 4: The Deal of the Century

By the summer of 1982, IBM had done something it did not fully understand: it had created a standard. The IBM PC, launched the previous August, was selling faster than anyone at the company had dared to forecast. But IBM had built its machine out of off-the-shelf parts and a published technical reference manual, and it had licensed its operating system, MS-DOS, from a scrappy outfit in Seattle on terms that let Microsoft resell that same software to anyone. IBM thought it was buying a product. It had actually opened a door — and a young company in Houston was about to walk right through it.

The clean room in Houston

Compaq Computer Corporation was founded on February 16, 1982 by three senior managers from Texas Instruments — Rod Canion, Jim Harris, and Bill Murto. The story goes that the first sketch of their product was drawn on a placemat in a Houston pie shop. Each founder chipped in $1,000 to start; venture capitalist Ben Rosen of Sevin Rosen Funds backed the idea, and the founders ultimately raised roughly $25 million to bring a machine to market. The name, a blend of “Compatibility and Quality,” announced the whole strategy in a single word.

The problem was that “compatibility” with IBM meant duplicating IBM’s BIOS — the small, copyrighted piece of firmware that let software talk to the hardware. Copy it outright and IBM’s lawyers would end you. So Compaq did something clever and expensive. Using a technique called clean-room reverse engineering, one team studied what IBM’s BIOS did and wrote a specification; a second team, walled off and having never seen IBM’s code, built a new BIOS that matched the behavior. The effort reportedly cost around $1 million. The result was legally clean and functionally identical — a BIOS that was not IBM’s but did everything IBM’s did.

The other half of the machine required no cleverness at all. To run the same software as an IBM PC, Compaq simply needed DOS — and Microsoft was standing there, delighted to sell it. That was the whole game.

The Portable that broke the records

Compaq announced its first product in November 1982 and shipped it in March 1983: the Compaq Portable, a 28-pound “luggable” that folded into a case the size of a sewing machine and sold for $2,995. It was not elegant, but it ran Lotus 1-2-3 and every other IBM PC program identically, and you could carry it out the door. Buyers did not care that it weighed as much as a small child. They cared that it worked exactly like the machine everyone was standardizing on.

The numbers that followed were the stuff of business-school legend. Compaq sold 53,000 units in its first year and booked about $111 million in revenue — at the time the largest first-year sales in American business history. It went public in 1983, and by 1986 it became the youngest company ever to reach the Fortune 500. By 1987 it crossed $1 billion in annual revenue faster than any startup before it. Compaq had proven that you did not need to be IBM to sell an IBM PC. You just needed the BIOS and the DOS.

The tax on the whole industry

Here is where the genius of Microsoft’s 1981 licensing deal reveals itself. IBM had paid a flat fee for the operating system, but Microsoft kept the right to license its own version, MS-DOS, to any manufacturer that wanted it. When Compaq succeeded, it did not just build one competitor to IBM — it published the recipe. Behind Compaq came a stampede: Tandy, Zenith, Kaypro, Leading Edge, and dozens more. Within roughly a year of the PC’s launch, Microsoft had licensed MS-DOS to more than 70 manufacturers. Compaq even shipped its own tailored build, Compaq-DOS, in late 1983.

Every one of those clone makers was locked in hand-to-hand combat with IBM and with each other over price, speed, and features. But on the one component none of them could clone — the operating system — they all quietly paid the same toll to the same company. Microsoft priced DOS to win, undercutting rivals like Digital Research’s CP/M-86, and let the clone wars do the selling. The fiercer the competition among hardware makers, the more copies of DOS shipped. Microsoft had found the rarest thing in business: a position where it profited no matter who won the fight below it.

There is a quiet irony in all of it. IBM’s open architecture was meant to get its own PC to market fast. Instead it turned the IBM PC into a public standard that anyone could build, and it handed Microsoft a software monopoly on that standard by default. DOS was not the best operating system of its era, and Microsoft did not even write most of it. But it was the one piece every “IBM compatible” had to have, and Microsoft owned the right to sell it. By the mid-1980s, MS-DOS was the main operating system for an entire category of machines that IBM had unintentionally franchised to the world.

The empire was built on a floppy disk. But a command line was starting to look like the past — and in a lab in Redmond, Microsoft was betting everything on a screen full of windows.

Next in the series: Part 6 — “Windows,” and Microsoft’s long, stumbling march from the C:\ prompt to the graphical interface that would define the PC.


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