Gary Kildall

Lore & Background

Gary Kildall was born and grew up in Seattle, Washington, where his family operated a seamanship school. After completing his doctorate, he fulfilled his draft obligation by teaching at the Naval Postgraduate School in Monterey, California. He demonstrated CP/M to Intel, but Intel had little interest and chose to market PL/M instead. Kildall and his wife Dorothy founded Digital Research, Inc. (originally named Intergalactic Digital Research) to market CP/M. The operating system became a de facto standard, and Kildall pioneered the concept of a BIOS to support increasing hardware variations. Gary left initial negotiations to his wife Dorothy while he used his private airplane to deliver software. Accounts disagree on whether he signed a non-disclosure agreement or met with IBM representatives. Various reasons have been given for the failure to reach an agreement, including DRI's unwillingness to sell for a one-time payment, scheduling concerns, and possible annoyance over the non-disclosure formality. According to Kildall, he and Dorothy negotiated further on a flight to Florida, reaching a handshake agreement, but IBM negotiator Jack Sams insisted he never met Gary. Bill Gates later characterized the story as Gary capriciously 'went flying.' IBM instead used 86-DOS from Seattle Computer Products, which implemented Kildall's CP/M application programming interface, and shipped it as IBM PC DOS. Kildall obtained a copy, concluded it infringed on CP/M, but was advised that intellectual property law for software was not clear enough to sue. He threatened legal action, and IBM offered to sell CP/M-86 as an option in return for a release of liabilit

Reader's Guide

Gary Kildall's creation of CP/M established the first widely adopted operating system for microcomputers, laying the groundwork for the personal computer revolution. His invention of the BIOS enabled software to function across diverse hardware, a concept that remains fundamental in computing. The failure to secure a deal with IBM for CP/M-86 allowed Microsoft's MS-DOS to dominate the market, shaping the trajectory of the PC industry. Kildall's later work included the Graphics Environment Manager (GEM), a graphical user interface, and he co-hosted the PBS program Computer Chronicles, which informed the public about personal computing trends. His contributions to early microcomputer software and operating systems are foundational, though his business decisions and the disputed IBM negotiations limited his commercial success.

Did You Know?

• He pioneered the BIOS concept to allow CP/M to operate on different hardware without modification.

Roots in Seattle and the Path to Computing

His father Joseph was a captain of Norwegian descent, while his mother Emma carried half Swedish blood—her grandmother had been born in Långbäck, in Skellefteå Municipality, before emigrating to Canada at twenty-three. This maritime, multigenerational backdrop shaped a young man who would eventually chart a very different course. He had once aspired to become a mathematics teacher, but his growing fascination with computer technology pulled him toward a doctoral program in Computer Science. His draft obligation took him to the Naval Postgraduate School in Monterey, California, where he taught.

Forging CP/M and the Digital Research Empire

Together with his wife Dorothy, Kildall founded a company originally called Intergalactic Digital Research, later renamed Digital Research, Inc., marketing CP/M through hobbyist magazine advertisements. As more manufacturers licensed the system, Kildall pioneered the BIOS—a set of simple programs stored in ROM or EPROM hardware—allowing CP/M to run across diverse machines without modification.

The IBM Meeting That Changed Everything

Gary had delegated initial negotiations to his wife Dorothy, as was his custom, while he and colleague Tom Rolander flew in Gary's private airplane to deliver software to manufacturer Bill Godbout. When IBM representatives arrived, they demanded Dorothy sign a non-disclosure agreement before explaining their purpose. On the advice of DRI attorney Gerry Davis, she refused without Gary's approval. He returned that afternoon, but accounts remain contradictory about whether he signed the NDA or even met the IBM team. Kildall claimed the representatives boarded the same flight to Florida that he and Dorothy took for their vacation, and that they reached a handshake deal mid-flight. IBM's Jack Sams insisted he never met Gary. Gates later told reporters that Gary capriciously "went flying." Sams left Gates with the task of sourcing a usable operating system, and weeks later proposed 86-DOS.

Pioneer, Educator, and Lasting Influence

Kildall is widely regarded as a pioneer of the personal computer revolution, and among the earliest figures to recognize microprocessors as fully capable computers rather than mere components. His work extended well beyond a single product: he created instruction set simulators INTERP/8 and INTERP/80 for Intel, developed the first high-level programming language for microprocessors, and built the architectural foundation that made microcomputers practical. In the 1980s, he stepped into the public eye as co-host of Computer Chronicles, a weekly PBS program that explored the latest developments in personal computing, bringing technical insight to a broad television audience. His story was later captured in Programmers at Work, a collection of interviews published by Microsoft Press.