ANSI INCITS 137 : 1988

1. Scope, Purpose, and Application
   1.1 Scope
   1.2 Purpose
   1.3 Application
   1.4 Conformance
2. Referenced Standards
   2.1 Referenced American National Standards
   2.2 Other Referenced Standards
3. Definitions
4. General Requirements
   4.1 Environment
   4.2 Materials
   4.3 Cartridge Assembly
5. Physical Requirements
   5.1 Dimensions and Tolerances
   5.2 Torque
   5.3 Physical Properties of Disk
   5.4 Magnetic Coating Resistivity
   5.5 Flammability
   5.6 Toxicity
6. Test Track Requirements (Track and Recording Information)
   6.1 Number
   6.2 Width
   6.3 Track Locations
   6.4 Physical Track Identification
7. Reference Surfaces
   7.1 Primary Standard Reference Surface(s)
   7.2 Secondary Standard Reference Surface(s)
8. Magnetic Characteristics
   8.1 Data Surfaces
   8.2 Signal Quality
Appendixes
   Appendix A Abrasivity Evaluation
      A1. Abrasivity
      A2. Comparative Disk
      A3. Wear Test Disk
      A4. Wear Revolution
      A5. Test Procedure
   Appendix B Compliance Test and Gauge for Cartridge
      B1. Purpose
      B2. Reference Zones
      B3. Load Force
      B4. Hub Shaft
      B5. Compliance
   Appendix C Roughness
   Appendix D Wear Resistance
   Appendix E Peak Shift Measurement
      E1. Measurement Conditions
      E2. Definition
      E3. Test Circuit
      E4. Timing Diagram
   Appendix F Dimensions
   Appendix G Drop-Through Gauge
   Appendix H Running Torque with Head(s) Loaded

Specifies the general, physical, and magnetic requirements for interchangeability of the one- and two-sided 90-mm (3.5-in) (nominal) flexible disk cartridge (for 7958 bits-per-radian (bpr) use) as required to achieve unformatted disk cartridge interchange among disk drives using 80 tracks per side and associated information processing systems. Defines the requirements and supporting test methods necessary to ensure interchange at acceptable performance levels.