What IT jobs existed before having computers?

The It jobs existing before full use of computers after evolution of IBM tabulatros and special room size computers during WWII were slighly increaed with induction of Main frames by IBM . We had type writers , Fax machines , slide projectros , copiers , and other machines. The clerical staff using electronics type writers , the staff working on priting machines , staff on fax machines and staff working in telecommunication tehnologies got integrated into computer staff during last two decades.