When in Rolm is the memoir of Jim Kasson, a key engineer at Rolm, the Silicon Valley startup that set out in the 1970s to challenge the Bell System.

Rolm began as a small computer company building rugged military systems. Within a few years it had become a leader in business telecommunications with the CBX, one of the first computer-controlled telephone switches. That innovation reshaped how companies used phones, fueled Rolm’s explosive growth, and ultimately led to its acquisition by IBM.

Kasson was there from the start, tasked with designing the CBX’s architecture and managing the project. His story traces the intense design work, the scramble of debugging early systems, and the culture clash of startup speed meeting big-company bureaucracy. Along the way he reveals the human side of engineering: the friendships formed, the pressures of hypergrowth, and the mix of luck and judgment that made the difference between failure and success.

More than a corporate history, When in Rolm captures what it felt like to be an engineer in Silicon Valley’s formative years, when bold ideas, relentless schedules, and sheer nerve created an industry.