ANSI INCITS 121 : 1984 : R2006

1 Scope, Purpose, and Application
  1.1 Scope
  1.2 Purpose
  1.3 Application
2 Referenced Standards
  2.1 American National Standard
  2.2 Other Standards
3 Definitions
4 General Requirements
  4.1 Environment
  4.2 Materials
  4.3 Disk Cartridge Assembly
5 Physical Requirements
  5.1 Dimensions
  5.2 Torque
  5.3 Physical Properties of the Coated Disk
  5.4 Disk Coating
  5.5 Magnetic Coating Resisitivity
  5.6 Flammability
  5.7 Toxicity
6 Test Track Requirements (Track and Recording Information)
  6.1 Number
  6.2 Width
  6.3 Location
  6.4 Physical Identification
  6.5 Index
7 Standard Reference Surfaces
  7.1 General
  7.2 Primary Standard Amplitude Reference Surfaces
  7.3 Secondary Standard Amplitude Reference Surfaces
8 Magnetic Characteristics
  8.1 Data Surfaces
  8.2 Signal Quality
Figures
Appendixes
Appendix A - Optic System
Figure A1 - Optic System for Light-Transmittance Measurement
            of Flexible Disk
Appendix B - Drop-Thru Test Gauge
Figure B1 - Drop-Thru Test Gauge
Appendix C - Abrasivity Evaluation
C1 - Comparative Disk
C2 - Wear Test Disk
C3 - Wear Revolution
C4 - Test Procedure

Describes the general, physical, and magnetic requirements for interchangeability of the two-sided, 8-in (200-mm) (nominal), 48-tracks- per-inch (tpi), flexible disk cartridge (for 13 262 flux transitions per radian (ftpr) use) as required to achieve unformatted disk cartridge interchange among disk drives using 77 tracks per side and associated information processing systems.