@tubetime You may be thinking of the IBM sychronized clock system, which would ‘clunk’ through the day in school rooms from the 1950’s through 90’s(?)

IBM sold its time equipment business division to Simplex in 1958, but faithful reproductions of the classroom clock design with a modern quartz movement rather than a synchronized master clock are still sold.

#IBM

From IBM’s archive: https://www.ibm.com/ibm/history/exhibits/cc/cc_room.html

A good article: https://medium.com/@steveharding_76362/a-vintage-ibm-clock-37bf77035ac0