Digital Equipment Corporation (DEC) was founded in 1957 by two MIT engineers. By 1988 it had grown to be the world's second largest computer corporation. From this heady height it took a mere 10 years for the company to disappear completely. This paper looks at DEC both in relation to the S-curve of technology and how it conformed to this model in the first thirty years but missed out on the disruptive technology of PCs and workstations in the late 1980s.Also how they did not see the wave in the late 1990s and missed the opportunity to lead the market once again.