From 1976 to 1981 my brother and I worked in a PCB manufacturer every Saturday morning and during college holidays. We used to programme and run these Excellon multi-spindle drilling and routing machines.
The drill rotational speed was 120,000RPM for 0.8mm to 1.0mm size holes. This was space age stuff in the day.
https://www.youtube.com/watch?v=lavSgjoaf7s
The drill bits were cooled by the air that sucked up the swarf. Tiny blockage and the drills would melt.
The hole positions were digitised and transferred to the machine control computers using punched paper tape like this.
https://www.youtube.com/watch?v=P6P_oiZWi_o