Information systems – contact start-stop storage disk – 95 840 flux transitions per track 7.874-in (2OO-mm) outer diameter and 2.500-in (63@5-mm) inner diameter
This standard provides the mechanical@ physical@ and magnetic properties of a magnetic disk with a 7.874-in (200-mm) diameter and low surface friction intended for mounting in data storage devices. A typical recording density is 480 tpi with 6858 flux transitions per inch (ftpi) at a radius of 2.224 in (56@49 mm). This standard defines the requirements and supporting test methods necessary to ensure acceptable performance levels in the context of the general application referenced above. It is distinct from a specification in that it delineates a minimum of restrictions consistent with compatibility of media characteristics. The performance levels contained in this standard represent the minimum acceptable levels of performance for typical applications. They@ therefore@ represent the performance levels that the media should meet or surpass during their useful life. The performance levels in this standard are intended as guidelines to prospective users and should not be employed as substitutes for purchase specifications. Quantitative performance levels that must be met or exceeded in order to comply with this standard are given wherever possible. In all cases@ including those in which quantitative limits for requirements falling within the scope of this standard are not stated but are left to agreement between interacting parties@ standard test methods and measurement procedures shall be used to determine such quantities.