How Exxon’s Investment Shaped the Z80 Microprocessor and Why It Did Not Become a Tech Giant

We all know IBM led the PC revolution, but few realize that oil giant Exxon once participated, ultimately leaving behind the famous Z80 processor. In 1974, Federico Faggin, who had helped design Intel’s 4004 and 8008 CPUs, left Intel because of its early‑morning schedule and founded Zilog.

Shortly after its founding, Exxon’s investment arm, Exxon Enterprises, began funding Zilog in 1975. With Exxon’s backing, Zilog created the Z80, one of the most important microprocessors in computing history, designed as a backward‑compatible improvement over Intel’s 8080.

Despite Exxon’s massive oil wealth and the popularity of the Z80, the company failed to become the next Apple or IBM. Its strategy was to acquire many tech firms to build an IBM‑like computer giant, which led IBM to refuse cooperation with Zilog—a disaster for a microcontroller designer. Eventually, Zilog’s managers and employees bought out Exxon’s shares.

Today, Exxon remains an oil company while Zilog is a key player in the embedded market. Had Exxon not been so aggressive, Zilog might have evolved into today’s Intel.