scope:

This standard specifies the general, physical, and magnetic requirements for interchangeability of the fivedisk pack, as required to achieve unrecorded pack interchange between disk storages and associated information processing systems. The five-disk pack, with five recording surfaces and one prerecorded servo surface, is of the type intended specifically for use with digital recording and reproduction equipments employing access mechanisms capable of positioning to 808 useable data tracks on each of the disk surfaces. The requirements for seven additional track areas on each recording surface are identified for use as alternates in case of difficulty in reading or recording on any useable data track.