Information Technology - One- and Two-Sided, Unformatted, 90-mm (3.5-in) 5,3-tpmm (135-tpi), Flexible Disk Cartridge for 7958 bpr Use - General, Physical and Magnetic Requirements Replaces ANSI X3.139-1988; Amendment 1: 1999
The standard specifies the general, physical and magnetic requirements for inter-changeability of the one-and two-sided 90mm (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.