Overview
ISO/IEC 11321:1992 - "Information technology - 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording - DATA/DAT format" defines a complete interchange standard for 3.81 mm (often written 3,81 mm) magnetic tape cartridges using helical-scan recording in the DATA/DAT format. The standard specifies the physical and mechanical case and tape characteristics, magnetic recording parameters, the recorded signal quality and formal DATA/DAT format, and the recording method so cartridges recorded on one drive can be read by another.
Keywords: ISO/IEC 11321, 3.81 mm magnetic tape cartridge, helical scan, DATA/DAT format, tape interchange, tape drive interoperability.
Key topics and requirements
- Physical case and tape dimensions: mandatory mechanical and dimensional requirements for the cartridge case, lid, hubs, label areas and optical detection windows to ensure consistent drive handling and insertion.
- Unrecorded tape characteristics: material, tape width, thickness, curvature, leader/trailer attachments, layer adhesion and tensile properties required across the full tape length.
- Magnetic recording characteristics: specifications for optimum recording field, average signal amplitude, resolution, overwrite behavior, ease of erasure, missing pulses and signal-to-noise ratio (S/N).
- DATA/DAT format and track layout: detailed frame/group/sub-group structures, main and sub-data blocks, pack items, group formats (Format 0/1), track geometry, azimuth arrangements, track pitch and track capacity for reliable helical-scan interchange.
- Recording method: definitions of physical recording density (flux transitions per mm), long-/short-term bit cell lengths, bit shift limits, read-signal amplitude and maximum recorded levels.
- Conformance rules: criteria for cartridges, generating systems (writers) and receiving systems (readers) to claim conformance.
- Environment and safety: specified test/operating/storage conditions (e.g., test conditioning: 23°C ±2°C, 40–60% RH) and handling recommendations.
- Test methods and annexes: annexes provide measurement methods (light transmittance, S/N, bit-shift, track-edge linearity, read-after-write, calibration tapes).
Applications and who uses it
- Ensures interchangeability of helical-scan DATA/DAT cartridges between drives and vendors.
- Used by tape drive and cartridge manufacturers, tape media suppliers, system integrators, data center and archival professionals, and forensic/data-recovery specialists working with legacy DAT media.
- Relevant for organizations maintaining long-term archives, migrating legacy DAT data, or developing compliant tape-drive hardware/firmware.
Related standards and notes
- Originated as ECMA-146 and adopted by ISO/IEC JTC 1.
- Contains normative references to related ISO/IEC standards (e.g., character sets, mechanical testing) and includes patent notices (noting existing patent interests and licensing references).
- Keywords for SEO: tape archival standard, magnetic tape interchange, DAT format standard, helical-scan tape specification.