ISO IEC 15895:1999 pdf download – lnformation technology – Datainterchange on 12,7 mm 128-trackmagnetic tape cartridges- DLT3-XTformat

ISO IEC 15895:1999 pdf download – lnformation technology – Datainterchange on 12,7 mm 128-trackmagnetic tape cartridges- DLT3-XTformat.
ISO IEC 15895 specifics the physical and magnetic characteristics of a 12,7 mm wide. I 28-track magnetic tape cartridge. to enable physical interchangeability of such cartridges between drives. Ii also specifies the quality of the recorded signals, a format – called Digital Linear Tape 3 Extended (DLT 3.XT – and a recording method, thereby allowing data interchange between drives. Together with a labelling standard, for instance International Standard ISO l(X)l for Magnetic Tape Labelling, it allows full data interchange by means of such magnetic tape cartridges.
2 Conformance
2.1 Magnetic tape cartridges
A magnetic tape cartridge shall be in conformance with this International Standard if it satisfies all mandatory requirements of this International Standard, The tape requirements shall be sdi.Iied throughout the extent of the tape.
2.2 Generating systems
A system generating a magnetic tape cartridge for interchange shall be entitled to claim conformance with this International
Standard if all the recordings that it makes on a tape according to 2.1 meet the mandatory requiremerns of this International
Standard.
In addition a claim of conformance shall state
— whether or not one, or more registered algorithm(s) are implemented within the system, and are able to compress data received from the host prior to collecting data into blocks, and
— the registered identification number(s) of the implemented algorithms
2.3 Receiving systems
A system receiving a magnetic tape cartridge for interchange shall be entitled to claim conformance with this International
Standard if it is able to handle any recording made on a tape according to 2.1.
In addition a claim of conformance shall state
— whether or not one, or more dc-compression algorithms) arc implemented witin the system, and arc able to be applied to dc-compress data prior to making such data available to the host, and
— the registered identification number(s) of the implemented algorithm(s)
3 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard, At the time of publication, the editions indicated were valid, All standards arc subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO I 001: I 986 Information processing – File structure and labelling of magnetic tapes for information interchange.
ISO 1302: 1992 Teclmical drawings – Method of indicating sumf ace texture.
ISO/IF.C 11576:1994 Infor,nation teclsnologi — Procedure for the registration of algorithms for the losskss compression of data.
4 Definitions
For the purposes of this international Standard. the following detinitions apply.
4.1 Average Signal Amplitude: The average peak-to-peak value of the output signal from the read head at the physical recording density of I 644) ftpmm measured over a minimum length of track of 25,4 mm. exclusive of missing pulses.
4.2 azimuth: The angular deviation, in degrees of arc. of the mean flux transition line of the recording made on a track from the line normal to the Reference Edge.
4.3 back surface: The surface of the tape opposite the magnetic coating which is used to record data.
4.4 Beginning-Of-Tape markers (BOT 1 and BOT 2): Two holes punched on the centreline of the tape towards the end nearest to the leader.
4.5 byte: An ordered set of bits acted upon as a unit.
Note- In this Intcrnilional Standard. all bytes are It-bit bytes.
4.6 cartrIdge: A case containing a single supply reel of 12,7 mm wide magnetic tape with a leader attached at the outer end.
4.7 Cyclic Redundancy Check (CRC) character: A 64-bit character, generated by a mathematical computation. used for error detection.
4.8 Farly Warning (FW): A signal generated by the drive indicating the approaching end of the recording area.
4.9 Frror-1)etecting Code (IDC): A mathematical computation yielding check bytes used for error detection.
4.10 Fnd-Of-Tape marker (FOT): A hole punched on the centreline of the tape towards the end farthest from the leader.
4.11 F.ntity: A group of twenty physical blocks treated as a logical unit and recorded on a logical track.
4.12 F.rror-Correcting Code (FCC): A mathematical computation yielding check bytes used for the correction of errors detected by the CRC and the EDC.
4.13 flux transition position: The point which exhibits thc maximum free-space tiux density normal to the tape surface.
4.14 flux transition spacing: The distance on the magnetic tape between successive flux transitions.
4.15 Logical Block: The two physical blocks simultaneously written on. or read from, the two physical tracks of a logical track.
4.16 logical track: A pair of physical tracks that are written or read simultaneously.
4.17 magnetic tape: A tape that accepts and retains magnetic signals intended for input, output, and storage purposes on computers and associated equipment.