1、 IL-STD-2179B 5 9999911 0096994 b i METRIC 1 MIL-STD-2179B 14 DECEMBER 1990 SUPERSEDING 24 DECEMBER 1987 NOTICE 1 I JULY 1987 30 JANUARY 1987 MIL-STO-2179A MIL-STD-2179(AS) MILITARY STANDARD HELICAL DIGITAL RECORDING FORMAT FOR 19-MM MAGNETIC TAPE CASSETTE RECORDER / REPRODUCERS AMSC NIA FCC 5895 OI
2、STRIBUTON STATEMENT A. Approvec for public release; dis,ribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2177B 58 = 7977911 007b775 W MIL-STD-21798 DEPARTMENT OF DEFENSE WASHINGTON, DC 20301 Helical Digital Recording For
3、mat for 19-mm Magnetic Tape Cassette Recorder/Reproducers 1. This military standard is approved for use by the Department of the Navy, and is available for use by all Departments and Agencies of the Depart- ment of Defense. 2. Beneficial comments (recommendations, additions, deletions) and any perti
4、nent data which may be of use in improving this standard should be Engineering and Standardization Department (Code 5313), Lakehurst, NJ 08733, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this standard or by 1 et ter. . addressed t
5、o: Commanding Officer, Naval Air Engineering Center, Systems I . ii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2177B 5 W 337771L 0076396 T I MIL-STO-2179B FOREWORD This standard was established to provide a means for operational military
6、 platforms to exchange digital data in the anti-submarine warfare, reconnaissance, intelligence and training communities. The standard defines the minimum requirements for compatibility and exchange of data and also allows designers to use one of several different approaches to implement compatible
7、hardware that will reproduce data which was recorded on another r manufacturers equipment conforming to this standard. iii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_. MIL-STD-2277B 58 m 7777721 0077068 7 IV Provided by IHSNot for ResaleNo repr
8、oduction or networking permitted without license from IHS-,-,-MIL-STD-2377B 5 U 7777733 007b777 L W Sect i on 1 . 1.1 1.2 1.3 2 . 2.1 2.1.1 2.2 2.3 3 . 3.1 3.2 3.3 3.4 3.5 3.6 3.2 3 8 MIL-STD-2179B . TABLE OF CONTENTS SCOPE . Purpose . Scope . Applicability . REFERENCED DOCUMENTS Government document
9、s Standards . Other publications Order of precedence . DEFINITIONS . 8/9 encoding Basic dimension . Byte Channel coding Codeword Codeword Digital Sum CDS) Derived dimension . Digital Sum Variation (DSV) . 3.9 Error correction 1 3.10 GaTois Field 3.11 Helical digital recorder . 3.12 Identification pa
10、ttern 3.13 Inner code block 3.14 Interleaving . . 3.15 Longit.udin 5.1.3.7.7 Extended control track . . Voic-e/time code 5.1.3.8 5.1.4 . Helical record- . 5-.1.4.1 Labeling convention Sector detai i c . 5.1.4.2 5.1.4.2.1 Sector preamble 5.1.4.2.1.1 Preamble .run-. up 5.1.4.2.1.2 Preamble dentifiqati
11、on pattern . 5.1.4.21 3 Preamb-le auxiliary data . 5.1.44.2 Data field . 5 .1.4. 2.3 I . Ou. ter errar protection . 5.1.4.2.4. Sy . 36 37 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- . . MIL-STD-ZL79B 58 W 99997LL 0096999 5 MIL-STD-2179B L TABLE
12、OF CONTENTS (Continued) Section 5.1.4.2.13 Transport start-up and stop . 5.2 Principal magnetic tape properties 5.2.1 Base material . 5.2.2 Magnetic coating 5.2.2.1 Coercivity 5.2.2.2 Orientation . 5.2.3 Tape . s ze . 5.2.3.2 5.2.3.3 5.2.5 I 5.2.3.1 Tape thickness . Delta width . Tape width 5.2.4 Re
13、ference edge straightness . 5.2.6 Offset yield strength . smissivity I 5.3 TaDe cassettes 5.3.1 5.3.2 5.3.3.2 5.3.4.1 5.3.4.2 5.3.4.4.1 5.3.5.1 5.3.6.1 5-3.2.1 5.3.7.2 5.3.8 Tran: Magnet n-+ , .i ct 1 _ aP *- e . Labe Loqi Usei vaLuIli piaiieh 5.3.2.2 Datum plane X . 5.3.2.3 Datum plane Y 5.3.3 Wind
14、ow and labels . 5.3.3.1 Label dimensions 1 location 5.3.4 Identification holes Purpose . . cal sense . 5.3.4.3 Manufacturers holes 5.3.4.4 User holes . . 5.3.4.5 5.3.5 Leader/trailer tape . 5.3.5.2 Material 5.3.5.3 Attachment 5.3.5.4 Width . 5.3.5.5 Thickness -.* 5.3*6 Reels .-. .- .- .- Locking . .
15、 5.3-6.2 Unlocking . .e . + . . .+ -. . 5J.6.3 ReeT spring . . - . -. - 5.3.7 Lid .C;C. ilocking - . . Opening . -. . .-. .-. 5.3.7.3 Closing . Tape path 5.3.9 Loading mechanism . 5.3.2.1 Datum plane Z . plug Dimensions and location I I . Length I I . I Ut 6.1 Tnte 8 . XITES . Subject term (key word
16、) listing . tnded use I J 6:; Changes from previous issue . Page 37 37 37 37 37 37 37 37 37 37 37 37 39 39 39 39 39. 39 39 39 39 39 49 49 49 49 4Y 50 50 50 50 50 50 50 50 50 5Q 50 50 50 50 50 61 61 bl 61 til 61 66 v Fi Provided by IHSNot for ResaleNo reproduction or networking permitted without lice
17、nse from IHS-,-,-_ MIL-STD-2179B 58 W 79977311 0047000 b W Figure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 31 3 2: 33 1 1 MIL-STD-2179B LIST OF FIGURES Record process signal flow (conceptual) . Location and dimensions of record track . Longitudinal heads location .
18、Servo control track format Servo reference signals . Time code . Sector details Data and ECC blocks . Row synchronization and identification Locations and dimensions of tolerance zones . Datum. support. and holding areas of small cassette . Datum. support. and holding areas of medium cassette Datum.
19、 support. and holding areas of large cassette . Bottom view of small cassette . Medium cassette. bottom and front views . Large cassette. bottom and front views Top and side view of small cassette . Top. rear. and end view of medium and large cassette Small cassette coding holes and user holes Mediu
20、m cassette coding holes and user holes . Large cassette coding holes and user holes Small. medium and large cassette reels Relationship between reel and reel table Small cassette reel lock and release Medium cassette reel lock and release Large cassette reel lock and release Lid lock and release Lid
21、 structure . Internal structure and tape path of small cassette (top view) (for reference only) . Internal structure and tape path of medium cassette (top view) (for reference only) . (top .view) (for. reference only) Minimum space for recorder/r.eproducer loading mechanism ANSI sync word . In-terna
22、1 structure and tape path of large cassette Page ci 7 8 11 12 14 15 16 19 23 38 40 41 42 43 44 45 46 47 48 51 52 53 54 55 56 57 58 59 62 63 64 65 . . . viii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Tab1 e Page I II III IV V VI VI I VI11 IX X .
23、 Record location and dimension 9 Data field patterns . 20 Outer error protection patterns . 21 8- to 9-bit map . 25 Code word mapping table . 36 Minimum tape length and nominal play time (at 240m bits/s user data rate) 39 Tape thickness 4Y Dimensions for bottom and side views of the medium and Dimen
24、sions for figure 24 (small. medium and large Tape coercivity . 49 large cassette . 60 cassette) 60 ix Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2177B 58 W 7977711 0077002 T MIL-STD-2179B 1. SCOPE 1.1 Purpose The purpose of this standard
25、 is to ensure the ability to exchan e digital data within the appropriate community of users in the Depart- 19-mm magnetic tape and to ensure that a recording made on one machine can be replayed on any other machine that conforms to this standard. ment o ? Defense, to standardize the cassettes and t
26、he format of the data for 1.2 Scope. This standard establishes the format of the data as recorded on the tape, the principal properties of the tape, and the dimensions and physical properties of three sizes of cassettes. 1.3 Applicability. This standard defines requirements for the purchase of magne
27、tic tape recorder/reproducers which record and reproduce or reproduce digital data using a rotary helical scan on 19-mm tape cassettes. 2. REFERENCED DOCUMENTS 2.1 Government documents. 2.1.1 Standards. Unless otherwise specified, the following s-andard of the issue listed in that issue of the Depar
28、tment of Defense Index of Specifi- cations and Standards (DODISS) specified in the solicitation forms a part of this standard to the extent specified herein. INTER-RANGE INSTRUMENTATION GROUP ( IKIG) 200- 70 IRIG RCC Time Code Standards (Application for copies should be addressed to Defense Logistic
29、s Agency, Defense Documentation Center, Cameron Station, Alexandria, VA 22314.) (Copies of standards required by contractors in connection with specific acquisition functions should be obtained from the contracting activity Qr as directed by the contracting officer.) The following documents form a p
30、art of this standard to the extent specified herein. not been adopted shall be those in effect on the date of the cited DODiSS. 2.2 Other publications. The issues of documents which have SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS SIVIPTE 224M Component Digital Video Recording - 19mm Type D-1
31、 Cassette- Tape Record SMPTE 225M Component Digital Video Recording - 1Ymm Type D-1 Cassette - Magnetic Tape SMP sw E 226M Component Digital vidt?O Recording - 19mm Type 0-1 Cassette - Tape Cassette E 227M Component Digital Video Recording - 19mm Type U-1 Cassette - Helical Data and Control Records
32、1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-ZL77B 58 77777LL 0077003 I MIL-STD-21796 SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEEKS (Continued) SMPTE 228M Component Digital Video Recording - 19mm Type D-1 Cassette - Cue and Time and
33、 Control Records Tape Transport Geometry Parameters for 19mm Type D-1 Format for Component Digital Video Recording SMPTE EG10 (Application for copies should be addressed to the Society of Motion Picture and Television Engineers, 595 West Hartsdale Avenue, White Plains, NY 10607.) 2.3 Order of preced
34、ence. In the event of a conflict between the text of this standard and the text of references cited herein, the text of this standard shall take precedence. Nothing in this document, however, supersedes applicble laws and regulations unless a specific exemption has been obtained. 3. DEFINITIONS 3.1
35、8/9 encoding. A method of encoding whereby an 8-bit data word is converted to a 9-bit code word in accordance with a conversion table. 3.2 Basic dimension. A fundamental d 3.3 Byte. A byte consists of eight b applied. - mension to wh nary digits. ch no tolerance is 3.4 Channel coding. The process by
36、 which binary data obtained from the digital logic circuits is converted to a waveform suitable for recording on magnetic tape. 3.5 Codeword. An 8/9 codeword consists of 9 binary digits. 3.6 Codeword Digital Sum (CDS). The digital sum variation from the beqinninq to the end of a codeword. CDS is cal
37、culated assuminci that the code- word polarity begins with a negative level and that the binary-levels are +1 and -1 and the transitions are centered in the bit cell. 3.7 Derived dimension. A derived dimension is obtained from other fundamental dimensions by computation and is given for informationa
38、l purposes only. 3.8 Digital Sum Variation (DSV). The running integral of the charge of the binary bit stream which will result in the coded NKZI(1) recording waveform. DSV is calculated assuming the binary levels are +1 and -1. 3.9 Error correction. The use of mathematically related check data, rec
39、orded with the digital data, to derive the errr symbols location and enable the correction of errors in the digital data. 3.10 Galois field. A galois field by GF (2Q) wnich consists of 2Q elements. operations of addition, subtraction, mult 2 s a“finite set of elements denoted This is a finite field
40、where the plication and aivision are closed, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2177B 58 9 7777721 007700LI 3 = MIL-STD-21798 3.11 Helical digital recorder. A helical-scan digital cassette tape recorder/reproducer . usi ng 19mm t
41、ype D-1 cassettes to record and/or reproduce digital data. 3.12 Identification pattern. Specific patterns used to identify sectors and array rows as described below. 3.13 Inner code block. An inner code block (horizontal in Figure 9) consists of 1 byte of block ID, 153 bytes of digital data followed
42、 by eight bytes of inner code check data for each row of each ErrorCorrection Code (ECC) array. 3.14 Interleaving. The systematic reordering of data so that originally adjacent bytes are separated, thus reducing the effect of burst errors on the. error correcting capability. 3.15 Longitudinal track
43、modulation method. The modulation method for recording digital data on the longitudinal track shall be Manchester encoding. This method results in a transition occurring at the beginning of every bit period. period from the start of a bit. transition within the bit. “One“ is represented by a second
44、transition one-half a “Zero“ is represented when there is no 3.16 Non-Return to Zero Inverse, Version 1, NRZI(1). A coding method where “1“ is denoted by a waveform transition in the center of a bit cell and a “O“ is denoted by no change. 3.17 Outer code block. An outer code block (vertical in Figur
45、e 9) consists of 118 bytes of digital data followed by ten bytes of outer code check data. 3.18 Postamble. A postamble consists of a sync pattern followed by an identification pattern. 3.19 Preamble. A preamble is the bit pattern recorded at the beginning of each helical track. pattern, an identific
46、ation pattern and auxiliary data. A preamble consists of a runup sequence, a sync 3.20 Randomization. The reduction of correlation in a serial bit sequence so that it statistically approximates a random sequence. 3.21 Reference dimension. A dimension, usually without tolerances, used for information
47、 purposes. - 3.22 Row identification pattern. lhe row identification pattern consists of one nine bit word which identifies each row of each data array “ within one sector. 3.23 Runup sequence. 3.24 Scrambling. An alternate term for randomization. A runup sequence is a bit pattern chosen to facilita
48、te the synchronization of data extraction circuits. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2377B 5 = 7799733 0077005 5 W MIL-STD-21798 3.25 Sector identification pattern. The sector preamble and postamble identification pattern con
49、sists of four consecutive 9 bit symbols which provide unique labeling of each sector recorded on tape. 3.26 Sync pattern. A sync pattern consists of four consecutive +bit words whose bit pattern is chosen to be a unique, compared to data. 3.27 Waveform polarity. The state of the codeword waveform at any spec- ific time as denoted
