The empirical investigation into the economic relevance of knowledge codification lacks behind the allied theoretical contributions. The article empirically examines the link between codifiable work content and code-based technologies. For this purpose, we use detailed information about the tasks that employees performed at their jobs, and the work devices assisting them, in West Germany, over a period of 27 years. The main results suggest that automation decreased both the explicit manual task content within occupations and the job security of occupations specialized in such tasks. Occupations which frequently performed explicit manual tasks were disproportionally concentrated in middle of the wage distribution, contributing to the widely-observed polarization of jobs.