Dorothy McEwen, 61, ex-wife of operating system pioneer

CARMEL VALLEY, Calif. -- Dorothy McEwen, the former wife of the software pioneer who lost to Microsoft the chance to supply IBM with the operating system for its first personal computer, died Monday at her Carmel Valley home. She had brain cancer and was 61.

The story of how Gary Kildall's Digital Research Inc. lost IBM's business at the birth of the PC industry is a Silicon Valley legend. Ms. McEwen, who was married to Kildall at the time, handled Digital Research's accounts with hardware companies such as IBM and played a role in the incident.

Today, all computers that run Microsoft's Windows are direct descendants of that first IBM PC. Microsoft Corp. cofounder Bill Gates is now the world's wealthiest person, his company the dominant supplier of the critical software.

But back in 1980, it was Gates who referred IBM to Kildall. At the time, the fledgling Microsoft did not have an operating system to sell to Big Blue. Kildall's Digital Research did. Kildall had started work on what would be the first commercial operating system, called CP/M, in the 1970s. He and his wife cofounded Digital Research to sell the software that ran early PCs like the Altair 8800.

They separated in 1983 and later divorced. Kildall died in 1994 after falling outside a Monterey restaurant.