ANSI INCITS 126-2017 pdf free download – One- or Two-Sided, Double-Density Unformatted, 5.25-Inch (130-mm), 96-tpi (3,8 tpmm), Flexible Disk Cartridge for 7958 bpr Use – General, Physical, and Magnetic Requirements.
1.1 Scope. This standard specifies the general, physi- cal, and magnetic requirements for interchangeability of the one- or two-sided, 5.25-inch (130.mm) (nomi- nal), 96-tracks-per-inch (tpi) (3,8-tracks-per-millimeter (tpmm)) flexible disk cartridge (for 7958-bits-per-radian (bpr) use) as required to achieve unformatted disk car- tridge interchange among disk drives using 80 tracks per side and associated information processing systems. The two-sided flexible disk cartridge enclosed in a pro- tective envelope and having two recording surfaces is of the type intended specifically for use with digital recording and reproducing equipment employing access mechanisms capable of positioning to these data tracks. There are three possible variations in the quan- tity of additional sector holes described in this stan- dard. Version A utilizes no sector holes, only a single index hole; Version B utilizes 10 sector holes in addi- tion to the index hole; and Version C utilizes 16 sector holes in addition to the index hole. These configura- tions are further described in 5 .1.3.3 and Figure 2. The existence and number of sector holes shall be specified by the user.
1.2 Purpose. This standard defines the requirements and supporting test methods necessary to ensure inter- change at acceptable performance levels. It is distinct from a specification in that it delineates a minimum of restrictions consistent with compatibility in inter- change transactions.
1.3 Application. The performance levels contained in this standard represent the acceptable levels of perfor- mance for interchange purposes. They therefore repre- sent the performance levels that the interchange items should meet or surpass during their useful life The per- formance levels in this standard are not intended to be employed as substitutes for purchase specifications. Wherever feasible, quantitative performance levels that must be met or exceeded in order to comply with this standard are given. In all cases, including those in which quantitative limits for requirements falling with- in the scope of this standard are not stated but are left to agreement between interchange parties, standard test methods and measurement procedures shall be used to determine such quantities. U.S. engineering units are the original dimensions in this standard. Conversions of toleranced dimensions from customary U.S. engineering units (similar to British Imperial Units) to SI units have been done in this standard according to Method A of American Na- tional Standard Metric Practice, ANSI/ASTM E380-76, ANSI/IEEE 268-1976 (and Toleranced Dimensions – Conversion from Inches into Millimetres and Vice Versa, IS0 370-1975) except as noted. For current conversions of toleranced dimensions, use Method A or B (as appropriate) as described in American National Standard Metric Practice, ANSI/IEEE 268-1982. Meth- od A should be used for economy unless a requirement for absolute assurance of a fit justifies use of Method B. In the national standards of IS0 member nations, addi- tional rounding may be done to produce “preferred” values. These values should lie within or close to the original tolerance ranges. Except as previously indicated, interchange parties complying with the applicable standards should be able to achieve compatibility without need for additional exchange of technical information.ANSI INCITS 126 pdf download.