Before being the leader of the team to develop the IBM PC he had been the lead manager for the development of the IBM Series/1 mini-computer. After this project was unsuccessful, he was said to have fallen out of grace with IBM and was reassigned to headquarters staff – a position that IBM employees often considered a form of penalty. His efforts to develop the IBM PC began when he took control of the IBM Entry Level Systems in 1980, with the goal of developing a low-cost personal computer to compete against increasingly popular offerings from the likes of Apple Computer, Commodore International, and other perceived IBM competitors. To create a cost-effective alternative to those companies' products, Estridge realized that it would be necessary to rely on third-party hardware and software. This was a marked departure from previous IBM strategy, which centered on in-house vertical development of complicated mainframe systems and their requisite access terminals. Estridge also published the specifications of the IBM PC, allowing a booming third-party aftermarket hardware business to take advantage of the machine's expansion card slots. The competitive cost and expandability options of the first model, IBM PC model 5150, as well as IBM's reputation, led to strong sales to both enterprise and home customers. Estridge was rapidly promoted, and by 1984 was IBM Vice President, Manufacturing, supervising all manufacturing worldwide. Steve Jobs offered Estridge a multimillion-dollar job as president of Apple Computer but he declined.
Death and legacy
Estridge and wife Mary Ann were killed in the crash of Delta Air Lines Flight 191 at Dallas/Fort Worth International Airport on August 2, 1985. He was 48 years old. The Estridges were survived by their three daughters. At the time of his death, IBM ESD, which included the development and manufacturing of the IBM PC, PC DOS, PC LAN and TopView, had nearly 10,000 employees and had sold over a million PCs. Estridge has been honored many times. In 1999, he was identified in CIO magazine as one of the people who "invented the enterprise". The Don Estridge High-Tech Middle School — formerly IBM Facility Building 051 — in Boca Raton, Florida, is named after him, and on the occasion of its dedication received from Don Estridge's family his personal IBM 5150 computer machines.