Overview
ISO/IEC 15718:1998 specifies the physical, magnetic and logical characteristics required to enable reliable data interchange on 8 mm wide magnetic tape cartridges using helical scan recording - the HH-1 format. The standard covers cartridge case dimensions and mechanics, unrecorded tape properties, recording method and format, track geometry, error control and media reference calibration so that cartridges recorded in one compliant drive can be read and used by another.
Key topics and requirements
- Physical and mechanical case requirements - dimensional features, windows, label areas, datum surfaces, lid and reel access to ensure mechanical interchangeability.
- Unrecorded tape characteristics - tape width, thickness, coating adhesion, layer-to-layer adhesion, tensile strength, winding and media recognition (MRS).
- Magnetic recording characteristics - required signal amplitude, resolution, overwrite behaviour, ease of erasure, and Signal‑to‑Noise Ratio (SNR) specifications.
- HH-1 recorded format and layout - frame definitions (pairs of azimuth-opposite tracks), sync blocks, data zones, system area, file marks (long/short), End of Data (EOD) and partition layouts.
- Track geometry and recording method - track pitch, track width, azimuth angles, bit cell and physical recording density (document references e.g. 3 658.1 ftpmm and Test Recording Current defined as 1.3× Standard Reference Current).
- Error detection and correction - use of CRC characters and Error Correcting Codes (ECC), plus optional ECC3 Block handling.
- Compression and registration - handling and declaration of registered lossless compression algorithms and their ID numbers per ISO/IEC 11576 requirements.
- Reference calibration - Master and Secondary Standard Reference Tapes (SSRT), Standard Reference Amplitude (SRA) and traceability for calibration.
- Test and measurement annexes - procedures for light transmittance, SNR, bit shift, track edge linearity and transportation recommendations.
Applications
- Ensures interchangeable data cartridges between different manufacturers’ drives and systems.
- Basis for tape drive design and firmware (read/write, format recognition, ECC handling, compression support).
- Reference for media manufacturers specifying tape substrate, coating and winding tolerances.
- Useful for data centers, archives and media services managing long-term storage, cartridge exchange and migration.
- Employed in test and calibration labs using SSRTs and Master reference tapes to verify read/write performance.
Who uses this standard
- Tape cartridge and magnetic media manufacturers
- Helical-scan tape drive designers and firmware engineers
- Systems integrators, data archivists and IT operations staff managing removable media
- Test laboratories and standards bodies involved in media calibration and compliance
Related standards
- ISO/IEC 11576 (registration of lossless compression algorithms)
- Applicable ISO and IEC mechanical, safety and testing standards referenced within ISO/IEC 15718
Keywords: ISO/IEC 15718, HH-1 format, 8 mm magnetic tape cartridge, helical scan recording, data interchange, tape format, track geometry, SNR, ECC, CRC, Standard Reference Tape.