BS ISO/IEC 12248:1993

1 Scope
2 Conformance
2.1 Magnetic tape cartridge
2.2 Generating system
2.3 Receiving system
3 Normative references
4 Definitions
4.1 Absolute Frame Number (AFN)
4.2 algorithm
4.3 Area ID
4.4 Automatic Track Finding (ATF)
4.5 Average Signal Amplitude
4.6 azimuth
4.7 back surface
4.8 byte
4.9 cartridge
4.10 Channel Bit
4.11 Codeword
4.12 Data Format ID
4.13 End of Data (EOD)
4.14 End of Information (EOI)
4.15 End of Partition (EOP)
4.16 entity
4.17 Error Correcting Code (ECC)
4.18 flux transition position
4.19 flux transition spacing
4.20 frame
4.21 group
4.22 Logical Beginning of Tape (LBOT)
4.23 Logical End of Tape (LEOT)
4.24 magnetic tape
4.25 master reference
4.26 Master Standard Amplitude Calibration Tape
4.27 Master Standard Reference Tape
4.28 Optimum Recording Field
4.29 partition
4.30 partition reference
4.31 Physical Beginning of Tape (PBOT)
4.32 Physical End of Tape (PEOT)
4.33 physical recording density
4.34 pre-recording condition
4.35 processed record
4.36 processed record sequence
4.37 processing
4.38 record
4.39 Reference Recording Field
4.40 Secondary Standard Amplitude Calibration Tape
4.41 Secondary Standard Reference Tape
4.42 Separator Mark
4.43 Standard Reference Amplitude
4.44 tape noise amplitude
4.45 Tape Reference Edge
4.46 track
5 Environment and safety
5.1 Testing environment
5.2 Operating environment
5.3 Storage environment
5.4 Transportation
5.5 Safety
5.6 Flammability
Section 2 - Requirements for the case
6 Dimensional and mechanical characteristics of the
      case
6.1 General
6.2 Overall dimensions
6.3 Loading grip
6.4 Holding areas
6.5 Notches of the lid
6.6 Lid dimensions
6.7 Optical detection of the beginning and end of tape
6.8 Bottom side
6.9 Hubs
6.10 Leader and trailer attachment
6.11 Interface between the hubs and drive spindles
6.12 Opening of the lid
6.13 Release of the hub locking mechanism
6.14 Label areas
Section 3 - Requirements for the unrecorded tape
7 Mechanical, physical and dimensional
      characteristics of the tape
7.1 Materials
7.2 Tape length
7.3 Tape width
7.4 Discontinuities
7.5 Total thickness
7.6 Longitudinal curvature
7.7 Cupping
7.8 Coating adhesion
7.9 Layer-to-layer adhesion
7.10 Tensile strength
7.11 Residual elongation
7.12 Electrical resistance of coated surfaces
7.13 Light transmittance of tape
8 Magnetic recording characteristics
8.1 Optimum recording field
8.2 Signal amplitude
8.3 Resolution
8.4 Overwrite
8.5 Ease of erasure
8.6 Tape quality
8.7 Signal-to-noise ratio (S/N) characteristic
Section 4 - Format
9 DATA/DAT-DC format
9.1 General
9.2 Basic Groups
9.3 Sub-groups
9.4 Sub-Data area
9.5 Basic Group structure
10 Method of recording
10.1 Physical recording density
10.2 Long-Term average bit cell length
10.3 Short-Term average bit cell length
10.4 Rate of change
10.5 Bit shift
10.6 Read signal amplitude
10.7 Maximum recorded levels
11 Track geometry
11.1 Track configuration
11.2 Average track pitch
11.3 Variations of the track pitch
11.4 Track width
11.5 Track angle
11.6 Track edge linearity
11.7 Track length
11.8 Ideal tape centreline
11.9 Azimuth angles
12 Recording of blocks on the tape
12.1 Recorded Main Data Block
12.2 Recorded Sub Data Block
12.3 Margin Blocks, Preamble Blocks and Postamble
      Blocks
12.4 Spacer Blocks
13 Format of a track
13.1 Track capacity
13.2 Positioning accuracy
13.3 Tracking scheme
14 Group Formats
14.1 Group Format 0
14.2 Group Format 1
14.3 Extended Gap Frames
14.4 Types of Groups
15 Magnetic tape layout
15.1 Load/Unload Area
15.2 Lead-in Area
15.3 Partition
15.4 EOI
15.5 Repeated Groups
15.6 Repeated Frames within a Normal Group
15.7 Relocation of Defective Groups
15.8 Appending
15.9 Overwrite
Annexes
A Measurement of the light transmittance of the
      prisms
B Recognition holes
C Means for opening the lid
D Measurement of light transmittance of tape and
      leaders
E Measurement of Signal-to-Noise Ratio
F Method for determining the nominal and the maximum
      allowable recorded levels
G Representation of 8-bit bytes by 10-bit pattern
H Measurement of bit shift
J Recommendations for transportation
K Method of measuring track edge linearity
L Read-After-Write
M Data allocation and C3 parity

Specifies the physical and magnetic characteristics of a 3,81 mm wide magnetic tape cartridge to enable interchangeability of such cartridges. Coverage includes definitions, flux transition position, master reference, loading grip, notches of the lid, datum holes, flux transition spacing, tape quality, residual elongation, yield strength, missing pulse zone, track geometry, and variation of the track pitch. Also gives detailed annexes.

This International Standard specifies the physical and magnetic characteristics of a 3,81mm wide magnetic tape cartridge to enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, the recorded format and the recording method, thereby allowing data interchange between drives by means of such magnetic tape cartridges. The format used is known as DATA/DAT-DC.

This International Standard specifies two types of cartridges which, for the purpose of this International Standard, are referred to as TypeA and TypeB.

For TypeA, the magnetic tape has a nominal thickness of 13μm and a nominal length of up to 60,5m.

For TypeB, the magnetic tape has a nominal thickness of 9μm a length of up to 92,0m.

Information interchange between systems by means of this International Standard also requires the use, at a minimum, of a labelling and file structure and an interchange code which are agreed upon by the interchange parties. It is not within the scope of this International Standard to specify the labelling and file structure, or the interchange code.