Chat script is simple in principle but in reality it is impossible to decode and make work. Your Own Chat Script Chat is actually easy to understand. The man page for chat is very good. Your problem in this case is the On-Track software and DOS itself. DOS suffers from a lack of foresight.
Any disk is made up of a combination of cylinders, heads and sectors per track.
DOS was originally written quite some time ago. The function that it uses to determine the disk geometry returns the number of cylinders in a value 10 bits wide. As anybody up to speed with their binary knows, this allows a value from 0-1023. As drives have grown, these values have also risen. There are two solutions.