Overview - ISO/IEC 18836:2001 (MammothTape-2)
ISO/IEC 18836:2001 defines an interchange format for 8 mm wide magnetic tape cartridges using helical scan recording in the MammothTape-2 format. The standard specifies the physical and magnetic characteristics of the cartridge and tape, the recorded signal quality, the recording method and the on-media format so that cartridges can be physically and logically interchanged between compliant drives and systems.
Key topics and technical requirements
- Physical case and tape dimensions: mechanical and dimensional requirements for the cartridge case (windows, datum areas, lids, reel access) and tape (length, width, thickness, leader/trailer/splice).
- Tape mechanical properties: material, tensile strength, residual elongation, layer-to-layer adhesion, tape winding and edge weave.
- Magnetic recording characteristics: test conditions, Typical Field and Standard Reference Amplitude (SRA), signal amplitude, resolution, signal‑to‑noise ratio, ease of erasure and overwrite behaviour. (The Test Recording Current - TRC - is defined relative to the Standard Reference Current.)
- Track format and logical layout: track definitions, physical block format (Logical Transfer Segment, Compression Unit, Physical Block, Information Matrix), track layout, servo areas and search-field structures.
- Recording method and geometry: physical recording density, long- and short-term bit cell lengths, bit shift, data signal amplitudes, track pitch, track width, azimuth angles and guard bands.
- Data integrity and processing: error detection and correction (CRC, ECC generation), pre-coder and randomisation, read-back checks and data formatting rules.
- Tape layout and metadata: partitions, Tape History Log (THL), file marks (short/long), set marks, PBOP/PBOP/PEOP definitions and end-of-data conventions.
- Environment, safety and testing: specified testing, operating and storage environments, transportation recommendations and flammability/safety notes.
- Conformance rules: requirements for cartridges, generating drives and receiving drives to claim compliance.
Applications and who uses it
ISO/IEC 18836 is used by:
- Tape and cartridge manufacturers for design and quality control.
- Magnetic tape drive designers to implement compatible helical-scan recording and servo/search mechanisms.
- Data center and archive managers ensuring media interchangeability and long-term data preservation.
- System integrators and OEMs requiring cross-vendor tape interchange.
- Standards and testing labs validating conformance (including calibration using the Master and Secondary Standard Reference Tapes).
Related standards
Normative references contained in the document include IEC 60950, ISO/IEC 11576 and ISO/IEC 15200. Annexes A–M are normative (measurement and ECC/CRC algorithms); Annex N provides informative transportation recommendations.
Keywords: ISO/IEC 18836, MammothTape-2, 8 mm magnetic tape, helical scan, tape cartridge, data interchange, track format, ECC, CRC, tape drive conformance.