Overview
ISO/IEC 22051:2002 defines the Super Digital Linear Tape 1 (SDLT1) format for 12.7 mm (12,65 mm) wide, 448‑track magnetic tape cartridges. The standard specifies the physical and magnetic characteristics of the tape and cartridge, the recorded signal quality, the recording method (including Laser‑Guided Magnetic Recording, LGMR), and the logical record and block formats to enable reliable data interchange and physical interchangeability between drives. SDLT1 is derived from the DLT format and supports about 110 Gbytes of uncompressed user data (typically ~220 Gbytes compressed).
Key Topics
- Physical characteristics: tape width (12.7 mm), thickness, reel/leader details, cartridge mechanics and handling, moment of inertia and winding, environmental and safety conditions for operation, storage and testing.
- Magnetic and optical technologies: LGMR with optically detected servo marks on the tape back surface for precise head positioning.
- Track architecture: 448 physical tracks; logical tracks are groups of eight physical tracks written/read simultaneously.
- Recording method & signal quality: test recording current, Standard Reference Amplitude (SRA), Typical Field definitions, read signal amplitude, channel bit-cell lengths and channel skew requirements.
- Data format & integrity: record, block, page, entity and envelope structures; CRC (64‑bit), EDC, ECC schemes; scrambler, modulation, precoder, preamble and sync fields; block types (EOTR, EOD, ECC blocks, Track ID blocks).
- Interchangeability & conformance: requirements for cartridges, generating systems and receiving systems to ensure any compliant drive can read/write exchanged tapes. Includes reference tapes (Master and Secondary) used for calibration.
- Test & measurement: servo signal-to-noise, missing pulses/zones, abrasivity, friction, tape durability; normative annexes provide measurement procedures and recommendations.
Applications
- Ensures tape drive interoperability and reliable long‑term data exchange between storage systems in data centers, archives and enterprises using SDLT1 cartridges.
- Used by tape cartridge manufacturers, tape drive designers, firmware developers, system integrators and test laboratories to validate mechanical, magnetic and logical conformance.
- Useful for organizations implementing backup, archival, or offline storage solutions where consistent physical interchange and data integrity across different vendors and drives is required.
Related Standards
- ISO 1001:1986 - File structure and labelling of magnetic tapes for information interchange (labelling for interchange).
- ISO 1302:2002 - Surface texture notation (referenced for surface specifications).
- ISO/IEC 11576:1994 - Registration of lossless compression algorithms (relevant for compression IDs in conformance statements).
Keywords: ISO/IEC 22051, SDLT1, 12.7 mm magnetic tape, 448-track cartridge, LGMR, Laser‑Guided Magnetic Recording, tape format, data interchange, tape drive interoperability, magnetic recording.