The expansion card ROM boot code attempts to boot from drive 1 of the controller by moving the read/write arm to track zero and attempting to read 256 bytes from sector zero of that track.
Laienduskaardi ROM laadimiskood üritas käivituda kohast 1 kontrolleril liigutades oma lugemis/kirjutamis "käe" rajale 0 ja üritas lugeda 256 baiti tolle raja sektorilt 0.