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, in 1979, he was assigned to manage a Series/1 special bid development group. This engineering and planning organization was responsible for responding to custom system solutions requested by large account sales and marketing representatives. One of the largest and most successful special bids ever won by IBM was the Series/1 Agent Computer System for the
State Farm Insurance company. In mid-1980, he was rewarded with the opportunity to lead IBM's efforts in the emerging personal computer business. His efforts to develop the IBM PC began when he took control of the IBM Entry Level Systems in 1980 (and was later named president of the newly formed IBM Entry Systems Division (ESD) in August 1983), 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, the
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==