1、INTERNATIONAL STANDARD ISO/IEC 13923 First edition 1996-l 2-15 Information technology - 3,81 mm wide magnetic tape cartridge for information interchange - Helical scan recording - DDS-2 format using 120 m length tape Technologies de /information - Cartouche de bande magn - the recording of multiple
2、representations of the same Basic Group; - the generation of ECC3 Frames. 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 process data received from the host prior to collecting the data into Basi
3、c Groups, and - the algorithm registration identification number(s) of the implemented algorithm(s). ISOIIEC 13923:1996(E) 0 ISO/IEC 2.3 Receiving system A system receiving a magnetic tape cartridge for interchange shall be entitled to claim full conformance with this International Standard if it is
4、 able to handle any recording made on the tape according to this International Standard. In particular it shall - be able to recognize repeated Frames and to make available to the host, data and Separator Marks from only one of these Frames; - be able to recognize multiple representations of the sam
5、e Basic Group, and to make available to the host, data and Separator Marks from only one of these representations; - be able to recognize an ECC3 Frame, and ignore it if the system is not capable of using ECC3 check bytes in a process of error correction; - be able to update the System Log(s) if the
6、 Write-inhibit Hole state so permits; - be able to recognize processed data within an Entity, identify the algorithm used, and make the algorithm registration number available to the host; - be able to make processed data available to the host. In addition a claim of conformance shall state - whethe
7、r or not the system is capable of using ECC3 check bytes in a process of error correction; - whether or not one or more Reprocessing algorithm(s) are implemented within the system, and are able to be applied to Processed Data prior to making such data available to the host; - the algorithm registrat
8、ion number(s) of the processing algorithm(s) for which a complementary Reprocessing algorithm is implemented. 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
9、 editions indicated were valid. All standards are 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 IS0 maintain regesters of curr
10、ently valid international standards. ISO/R 527: 1966, Plastics - Determination of tensile properties. IS0 1302: 1992, Technical drawings - Method of indicating surface texture. ISO/IEC 11576: 1994, Information technology - Procedure for the registration of algorithms for the lossless compression of
11、data. IEC 950 :1991, Safety of information technology equipment including electrical business equipment. 4 Definitions For the purposes of this International Standard, the following definitions apply. 4.1 4.2 4.3 4.4 4.5 4.6 2 Absolute Frame Number (AFN) : A sequence number, encoded in the Frame. a.
12、c. erase : A process of erasure utilising magnetic fields of decaying intensity. Access Point : A point, at the start of a processed record sequence, at which the presentation of Codewords to a reprocessing algorithm is required to start, regardless of whether the data of interest in a retrieval ope
13、ration starts at that point or at a subsequent point. Algorithm : A set of rules for transforming the logical representation of data. Area ID : An identifier defining the area of the tape and specifying the types of Frame written. Automatic Track Finding (ATF) : The method by which tracking is achie
14、ved. 0 ISO/IJx ISO/IEC 13923:1996(E) 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25 Average Signal Amplitude : The average peak-to-peak value of the output signal from the read head at the fundamental frequency of the specified physical recording density
15、over a minimum of 7,8 mm of track, exclusive of missing pulses. azimuth : The angular deviation, in degrees, minutes and seconds of arc, made by the mean flux transition line with the line normal to the centreline of the recorded track. back surface : The surface of the tape opposite to the magnetic
16、 coating which is used to record data. byte : An ordered set of bits acted upon as a unit. cartridge : A case containing magnetic tape stored on twin hubs. Channel bit : A bit after 8- 10 transformation. Codeword : A word which is generated by a processing algorithm. The number of bits in a Codeword
17、 is variable, and is not defined by this International Standard. Data Format ID : An identifier specifying which data format is being used on the tape. Early Warning Point (EWP) : A point along the length of the tape at which warning is given of the approach, in the forward direction of tape motion,
18、 of the partition boundary or of the Physical End of Tape. End of Data (EOD) : The point on the tape at the end of the group which contains the last user data. Entity : A unit of recorded data, comprising a Processed Record Sequence preceded by housekeeping information. Error Correcting Code (ECC) :
19、 A mathematical computation yielding check bytes used for the detection and cor- rection of errors. flux transition position : That point which exhibits maximum free-space flux density normal to the tape surface. flux transition spacing : The distance along a track between successive flux transition
20、s. Frame : A pair of adjacent tracks with azimuths of opposite polarity, in which the track with the positive azimuth precedes that with the negative azimuth. Housekeeping Frame : A Frame which contains no user data and which is identified as such by the values in the data fields therein. Logical Be
21、ginning of Tape (LBOT) : The point along the length of the tape where a recording of data for interchange commences. magnetic tape : A tape which will accept and retain the magnetic signals intended for input, output and storage purposes on computers and associated equipment. Master Standard Amplitu
22、de Calibration Tape : A pre-recorded tape on which the standard signal amplitudes have been recorded in the tracks of positive azimuth, 21 pm wide, recorded at a track pitch of 27,2 m, on an a.c. erased tape. Note 1 - The tape includes recordings made at 83.3 ftpmm, 333.3 ftpmm, 500 ftpmm. 1 000,O f
23、tpmm and 1 499.9 ftpmm. Note 2 - The Master Standard Amplitude Calibration Tape has been established by Reliability Centre for Electronic Components of Japan (RCJ). ISO/IEC 13923:1996(E) 0 ISO/IEC 4.26 4.27 4.28 4.29 4.30 4.31 4.32 4.33 4.34 4.35 4.36 4.37 4.38 4.39 4.40 4.41 4.42 4.43 Master Standa
24、rd Reference Tape : A tape selected as the standard for Reference Recording Field, Signal Ampli- tude, Resolution, Overwrite and Signal-to-Noise Ratio. Note 3 - The Master Standard Reference Tape has been established by RCJ. Optimum Recording Field : In the plot of Average Signal Amplitude against t
25、he recording field at the physical recording density of 2 999,9 ftpmm, the field that causes the maximum Average Signal Amplitude. Partition Boundary : The point along the length of a magnetic tape at which partition 1 ends and partition 0 commences. Physical Beginning of Tape (PBOT) : The point whe
26、re the leader tape is joined to the magnetic tape. Physical End of Tape (PEOT) : The point where the trailer tape is joined to the magnetic tape. physical recording density : The number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre (ftpmm). pre-r
27、ecording condition (see annex F) : The recording levels above which a tape intended for interchange shall not previously have been recorded. processing : Ihe use of an algorithm to transform host data into Codewords. processed data : A sequence of Codewords which results from the application of proc
28、essing to data. Processed Record : A sequence of Codewords which results from the application of processing to an Unprocessed Record. Processed Record Sequence : A sequence of one or more Processed Records which starts on an g-bit boundary and ends on a subsequent g-bit boundary. record : Related da
29、ta treated as a unit of information. Reference Recording Field : The Optimum Recording Field of the Master Standard Reference Tape. reprocessing : The use of an algorithm to transform Codewords into data as required by the host. Secondary Standard Amplitude Calibration Tape : A tape pre-recorded as
30、defined for the Master Standard Amplitude Calibration Tape; the outputs are known and stated in relation to those of the Master Standard Amplitude Calibration Tape. Note 4 - Secondary Standard Amplitude Calibration Tapes can be ordered from RCJ, l-l-12 Hachiman-cho, Higashikurume. Tokyo 203, Japan,
31、under Part Number JCM 6129 until the year 2005. It is intended that these be used for calibrating tertiary reference tapes for use in routine calibration. Secondary Standard Reference Tape : A tape the performance of which is known and stated in relation to that of the Master Standard Reference Tape
32、. Note 5 - Secondary Standard Reference Tapes can be ordered from RCJ, I- 1- 12 Hachiman-cho, Higashikurume, Toyko 203, Japan, under Part Number JRM 6129 until the year 2005. It is intended that these be used for calibrating tertiary reference tapes for use in routine calibration. Separator Mark : A
33、 record containing no user data, which is used to separate data. Standard Reference Amplitude : The Average Signal Amplitude from the tracks of positive azimuth of the Master Standard Amplitude Calibration Tape at a specified physical recording density. 0 ISO/IEC ISO/IEC 13923: 1996(E) 4.44 Tape Ref
34、erence Edge : The bottom edge of the tape when viewing the recording side of the tape, with the PEOT to the observers right. 4.45 Test Recording Current : The current that produces the Reference Recording Field. 4.46 track : A diagonally positioned area on the tape along which a series of magnetic s
35、ignals may be recorded. 4.47 unprocessed data : Data which has not been subjected to processing. 4.48 Unprocessed Record : A record of unprocessed data, comprising an integral number of bytes. 4.49 Virtual End of Tape (VEOT) : The point along the length of the magnetic tape within partition 1 which
36、defines the end of the part of partition 1 which is usable for recording data for interchange. 5 Environment and safety Unless otherwise stated, the conditions specified below refer to the ambient conditions of the air immediately surrounding the cartridge. 5.1 Testing environment Unless otherwise s
37、tated tests and measurements made on the tape cartridge to check the requirements of this International Standard shall be carried out under the following conditions: temperature : 23 “C + 2 “C relative humidity : 40 % to 60 % conditioning period before testing : 24 h 5.2 Operating environment Cartri
38、dges used for data interchange shall be capable of operating under the following conditions: temperature :5”Cto45”C relative humidity : 20 % to 80 % wet bulb temperature : 26 “C max. There shall be no deposit of moisture on or in the cartridge. Conditioning before operating: If a cartridge has been
39、exposed during storage and/or transportation to a condition outside the above values, before use the cartridge shall be conditioned in the operating environment for a time at least equal to the period during which it has been out of the operating environment, up to a maximum of 24 h. Note 6 - Rapid
40、variations of temperature should be avoided. 5.3 Storage environment For long-term or archival storage of cartridges the following conditions shall be observed: temperature : 5 “C to 32 “C relative humidity : 20 % to 60 % wet bulb temperature : 26 “C max. The stray magnetic field at any point on the
41、 tape shall not exceed 4 000 A/m. There shall be no deposit of moisture on or in the cartridge. 5.4 Transportation Recommended limits for the environment to which a cartridge may be subjected during transportation, and the precautions to be taken to minimize the possibility of damage, are provided i
42、n annex J. 5 ISO/IEC 13923: 1996(E) 0 ISO/IEC 5.5 Safety The cartridge and its components shall satisfy the requirements of IEC 950. 5.6 Flammability The cartridge and its components shall be made from materials, which if ignited from a match flame, do not continue to burn in a still carbon dioxide
43、atmosphere. 0 ISO/IEC ISOIIEC 13923:1996(E) Section 2 - Requirements for the case 6 Dimensional and mechanical characteristics of the case 6.1 General The case of the cartridge shall comprise - an upper half, - a lower half, - a slider movably mounted on the lower half, - a lid pivotally mounted on
44、the upper half. In the drawings, using third angle projection, an embodiment of the cartridge is shown as an example. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figures 19,
45、 20 Figures 2 1, 22 Figure 23 is a perspective view of the cartridge seen from top. is a perspective view of the cartridge seen from bottom. is a partial view of the rear side. is a schematic view showing the Reference Planes X, Y and Z. shows the front side. shows the top side with the lid in close
46、d position. shows the left side. shows the top side with the lid in open position. shows the left side with the lid in open position. shows the bottom side with the lid and the slider in closed position. shows the bottom side with the lid and the slider in open position. is a view from the top of th
47、e inside of the lower half with the upper half removed. is a view of the bottom half with the lid and the slider in open position. is a view of the left side with the lid and the slider in open position. is a top view of a hub. is a side view of a hub with partial cross-section. is a partial cross-s
48、ection through a hub and both halves of the case showing the interface with the drive spindle. shows at a larger scale the lid in the open position. show at a larger scale the functional relationship between the lid and the locking mechanism of the hubs. show the label areas on the top and the rear
49、side. shows both corners of the bottom side, for autoloaders. The dimensions are referred to three orthogonal Reference Planes X, Y and Z (figure 4). Plane X is perpendicular to Plane Z and passes through the centres of both the circular and elongated Datum Holes, revealed when the slider is opened (see 6.8.4 and figure 11). Plane Y is perpendicular to Plane X and Plane Z and passes through the centre of the circular Datum Hole. Plane Z is the plane on which the slider moves (see figure 7). 6.2 Overall dimensions (figures 6 and 7) The overall dimensions of the case with the lid in the close
