As I mentioned in an early post the roots of COS were laid in the late 60ies of the 20th century.
Close to that time, BLISS was designed at Carnegie-Mellon University (January 15, 1970)
https://en.wikipedia.org/wiki/BLISS
Similarly in 1972 C language was written at Bell Labs.
https://www.bell-labs.com/usr/dmr/www/chist.html