This was probably Econet and network !boot stuff. That was horribly slow. Stand-alone boot was about 5 seconds.

Usually the schools has MDFS filers from BBC days being repurposed as econet servers which could barely cope with the load of a room full of machines coming up.

The IBM compatibles that seemed to replace them from RM were complete dogshit. Fortunately they killed that half way through the rollout when my sister was at school and went full netware instead.

I’m feeling old now.