Compaq Computer Corporation was founded in early 1982 by Rod Canion, Jim Harris, and Bill Murto, three managers who had left the semiconductor company Texas Instruments. Their first product was the Compaq Portable, a luggable computer designed to run the same software as the IBM Personal Computer. To do that, Compaq had to solve the problem that defined the early PC industry: how to be fully IBM-compatible without infringing IBM’s copyrights.
The barrier was the BIOS. The IBM Personal Computer Technical Reference of August 1981 had published the complete source listing of IBM’s system BIOS, which meant that the behavior was knowable but the code itself was copyrighted. Compaq could buy the same Intel processor and license the same Microsoft operating system as IBM, but it could not lawfully copy the BIOS source printed in IBM’s manual. Anyone who had read that listing was legally tainted and could not safely write the replacement.
Compaq’s solution was a clean-room reverse-engineering process. Engineers who had studied IBM’s published BIOS wrote a precise specification of what it did, and a separate group of programmers, who had never seen IBM’s code, implemented firmware that matched that behavior. The result was Compaq’s own independently authored BIOS. The surviving hardware records the outcome directly: the Compaq Portable’s system board carries the copyright string “(C) COMPAQ COMPUTER CORP. 1982,” a distinct work that nonetheless ran IBM PC software faithfully.
Compaq’s achievement was both commercial and structural. The company grew explosively on the strength of its compatible machines, but its larger legacy was proving that a legal 100-percent-compatible clone was possible at all. That proof opened the floodgates: once compatibility could be reached without copying IBM’s code, the PC ceased to be IBM’s proprietary product and became an open standard that the rest of the industry, and ultimately Microsoft and Intel, would build upon.