After I got my SM degree, I took some enforced time off from astronomy
due to a lack of jobs and developed financial software in Boston at
Publishing Company in 1975 and 1976, while still doing some work
at MIT in my spare time.
In 1976, I left to develop astronomical software full-time, in lieu
of graduate school, at
Cornell University in
Ithaca, New York from 1976
until 1979, when my research group moved to M.I.T., where I worked until 1984.