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ECMA 248 : 2ED 98
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12,65 MM WIDE MAGNETIC TAPE CARTRIDGE FOR INFORMATION INTERCHANGE - HELICAL SCAN RECORDING - DTF-1 FORMAT
12-01-2013
Section 1 - General
1 Scope
2 Conformance
2.1 Magnetic tape cassette
2.2 Generating system
2.3 Receiving system
3 References
4 Definitions
4.1 Absolute block number
4.2 a.c. erase
4.3 algorithm
4.4 Append file
4.5 Append volume
4.6 Average Signal Amplitude (ASA)
4.7 azimuth
4.8 back surface
4.9 bit cell
4.10 block
4.11 Block Management Table (BMT)
4.12 byte
4.13 cassette
4.14 compressed data
4.15 Control Track
4.16 flux transition position
4.17 flux transition spacing
4.18 Logical track set ID
4.19 Logical volume
4.20 magnetic tape
4.21 Master Standard Reference Tape (MSRT)
4.22 physical recording density
4.23 Reference Field (RF)
4.24 Secondary Standard Reference Tape (SSRT)
4.25 Standard Reference Amplitude (SRA)
4.26 Standard Reference Current (Ir)
4.27 Tape Reference Edge
4.28 Test Recording Current (TRC)
4.29 track
4.30 track angle
4.31 Track Set
4.32 Typical Field (TF)
4.33 Unique Identifier (UID)
4.34 word
5 Conventions and notations
5.1 Representation of numbers
5.2 Names
6 Acronyms
7 Environment and safety
7.1 Testing environment
7.2 Operating environment
7.3 Storage environment
7.4 Transportation
7.5 Safety
7.6 Flammability
Section 2 - Requirements for the case
8 Dimensional and mechanical characteristics of the case
8.1 General
8.2 Type S cassette
8.2.1 Overall dimensions
8.2.2 Holding areas
8.2.3 Window
8.2.4 Label areas (figure 4)
8.2.5 Datum areas and datum holes
8.2.6 Support areas
8.2.7 Guiding grooves
8.2.8 Recognition holes
8.2.9 Write-inhibit plug
8.2.10 Pre-positioning surface
8.2.11 Cassette lid
8.2.12 Cassette reel lock
8.2.13 Reel access holes
8.2.14 Reels
8.2.15 Position of the tape in the case
8.2.16 Tape path zone
8.2.17 Tape access cavity
8.3 Type L cassette
8.3.1 Overall dimensions
8.3.2 Holding areas
8.3.3 Window
8.3.4 Label areas
8.3.5 Datum areas and datum holes
8.3.6 Support areas
8.3.7 Guiding grooves
8.3.8 Recognition holes
8.3.9 Write-inhibit plug
8.3.10 Pre-positioning surface
8.3.11 Cassette lid
8.3.12 Cassette reel lock
8.3.13 Reel access holes
8.3.14 Reels
8.3.15 Position of the tape in the case
8.3.16 Tape path zone
8.3.17 Tape access cavity
8.3.18 Cavity for compatibility with Type S
cassette
Section 3 - Requirements for the unrecorded tape
9 Mechanical, physical and dimensional characteristics
of the tape
9.1 Materials
9.2 Tape length
9.3 Tape width
9.4 Width and position of splicing tape
9.5 Discontinuity
9.6 Tape thickness
9.7 Longitudinal curvature
9.8 Out-of-plane distortions
9.9 Coating adhesion
9.10 Layer-to-layer adhesion
9.11 Tensile strength
9.11.1 Breaking strength
9.11.2 Yield strength
9.11.3 Strength of Splice
9.12 Residual elongation
9.13 Electrical resistance of the coated surfaces
9.14 Tape wind
10 Magnetic recording characteristics
10.1 Typical Field TF1
10.2 Average Signal Amplitude (ASA)
10.3 Resolution
10.4 Signal-to-noise ratio (S/N)
10.5 Ease of erasure
10.6 Tape quality
10.6.1 Missing pulses
10.6.2 Missing pulse zone
10.7 Inhibitor tape
Section 4 - Requirements for an interchanged tape
11 Format for helical tracks
11.1 General description of the write data path (see
figure 42)
11.2 Formation of a Logical Track Set
11.2.1 Types of information track sets
11.2.2 Generation of a Logical Track Set
11.2.3 Subcode data field
11.2.4 BMT
11.2.5 Data and information field definitions
11.3 Track Set information
11.3.1 Loading the Product Code Arrays
11.4 Product code array processing
11.4.1 Error correction method
11.4.2 Error correction coding for C1 Parity
11.5 Track assignments
11.5.1 Sectors
11.5.2 Sync Blocks
11.5.3 Track interleave
11.5.4 Track Sync Blocks
11.5.5 Byte interleave across Sync Blocks
11.5.6 Randomization
11.6 Formation of the contents of a helical track
11.6.1 Sector details
11.7 Channel bit coding
11.7.1 General
11.7.2 Interleaved-NRZ1
12 Track geometry
12.1 General
12.2 Helically recorded tracks
12.2.1 Location of the tracks
12.2.2 Track width
12.2.3 Track angle
12.2.4 Track pitch
12.2.5 Location of elements in the helical track
12.2.6 Location of the Data Area Reference Point
12.2.7 Straightness of tracks
12.2.8 Azimuth angles
12.2.9 Tracking Pilot Signal (TPS)
12.2.10 Amplitude of servo signals
12.3 Longitudinal tracks geometry
12.3.1 Control Track
12.3.2 Time Code Track signals recording position
13 Method of recording helical tracks
13.1 Physical recording density
13.2 Record current optimization
13.3 Efficiency of erasure
14 Method of recording longitudinal tracks
14.1 Overview
14.2 Control Track
14.2.1 Signal
14.2.2 Polarity of magnetisation
14.2.3 Alignment
14.2.4 Read signal amplitude
14.2.5 Quality of the Control Track
14.3 Time Code Track
14.3.1 Method of recording the Time Code Track
14.3.2 Physical recording density
14.3.3 Bit shift
14.3.4 Read signal amplitude
14.3.5 Quality of the Time Code Track
14.4 Format for the Time Code Track
14.4.1 Count bits
14.4.2 Phase bit
14.4.3 Synchronizing pattern
14.4.4 Supplemental Data
14.4.5 Extent of Time Code
Section 5 - Requirements for recorded information
15 Recorded information
15.1 Recording area
15.2 Magnetic tape layout
15.2.1 Valid data areas
15.2.2 Invalid data areas
15.3 Physical TSID
15.3.1 Structure surrounding the VSIT area
15.3.2 Structure of the DIT area
15.3.3 Structure of the User Data Area
Section 6 - Write operations
16 Write retry sequence
17 Append file operation
17.1 Append volume
17.2 Append write
17.3 Overwrite
17.4 File extension
Annex A - Measurement of Signal-to-Noise Ratio
Annex B - Representation 8/9 coding patterns
Annex C - Recommendations for Transportation
Annex D - Inhibitor Tape
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