《ANSI-INCITS-181-1990-R2006.pdf》由会员分享，可在线阅读，更多相关《ANSI-INCITS-181-1990-R2006.pdf（26页珍藏版）》请在三一文库上搜索。
1、ANSI INCITS 181-1990 (R2001) (formerly ANSI X3.181-1990 (R2001) for Information Systems Recorded Magnetic Tape and Cartridge for Information Interchange 112 inch (12.65 mm), Serial Serpentine, 22-Track, 6 667 bpi (262 bpmm), and 48-Track, 10 000 bpi (394 bpmm), MFM-Encoded Requirements for Recording
2、 Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright American National Standards Institute
3、 Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI X3.1 81-1990 American National Standard for Information Systems - Recorded Magnetic Tape a
4、nd Cartridge for Information Interchange - l/2 inch (12.65 mm), Serial Serpentine, 22-Track, 6 667 bpi (262 bpmm), and 48-Track, IO 000 bpi (394 bpmm), MFM-Encoded - Requirements for Recording Secretariat Computer and Business Equipment Manufacturers Association Approved January 16,199O American Nat
5、ional Standards Institute, Inc Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- American National
6、 Standard Approval of an American National Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial ag
7、reement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of
8、 American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National S
9、tandards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Instit
10、ute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that
11、 action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Published by American National Standards Institute 11 West 42nd St
12、reet, New York, New York 10036 Copyright 1990 by Information Technology Industry Council (ITI) All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of ITI, 1250 Eye Street NW, Washington, DC 2
13、0005. Printed in the United States of America Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- Fo
14、reword (This Foreword is not part of American National Standard X3.181-1990.) This standard presents format and recording requirements for l/2 inch (12.65 mm), 22- or 48-track magnetic tape, to be used for information interchange among processing systems, communication systems, and associated equipm
15、ent utilizing a standard code for interchange. This standard deals solely with recording on magnetic tape. The X3B.5 Subcommittee on Magnetic Tape, which developed this standard, consists of experienced and qualified specialists in recording digital information on magnetic tape. In the development o
16、f this standard, careful consideration was given to current practices, existing equipment and supplies, and the broadest possible acceptance, and to providing a basis for future improvements in the use of this cartridge medium. Requests for interpretation, suggestions for improvement or addenda, or
17、defect reports are welcome. They should be sent to the X3 Secretariat, Computer and Business Equip- ment Manufacturers Association, 3 11 First Street, NW, Suite 500, Washington, DC 20001-2178. This standard was processed and approved for submittal to ANSI by American National Standards Committee on
18、Information Processing Systems, X3. Committee approval of the standard does not necessarily imply that all committee members voted for its ap- proval. At the time it approved this standard, the X3 committee had the following members: Richard Gibson, Chair Donald C. Loughry, Vice-Chair Jean-Paul Emar
19、d, Administrative Secretary Organization Represented Name of Representative Allen-Bradley Company . Ronald H. Reimer American Library Association Paul Peters American Nuclear Society Geraldine C. Main AMP, Inc Sally Hartzell (Ah) . Edward Kelly Apple Computer, Inc Ronald Lloyd (Alt) . Karen Higginbo
20、ttom Michael J. Lawler (Alt) Apple Professional Users Group . Ira Wilson Association of the Institute for Certification of Computer Professionals Kenneth Zemrowski Eugene M. Dwyer (Alt) AT or +2 percent, - 2.6 percent, for low density. As shown in Figure 2, the time between adjacent peaks in the 11
21、interval is denoted as Tl. The time between the last 1 in the 11 interval and the last 1 in the following 11 interval is denoted as To. Peak Shift = 3T,-T, l 100 4.4 Read Signal Amplitude. The signal amplitude shall be measured at a point in the read channel where the signal is proportional to the r
22、ate of change of flux in the read head. The average signal amplitude of an interchanged cartridge averaged over a minimum of 1.0 inch (25.4 mm) at the recording density, shall be between 75 percent and 125 percent of the standard reference amplitude. Averaging for the interchange cartridge may be se
23、gmented into blocks. No dropouts are allowed within the measured area. Traceability to the standard reference amplitude is provided by the calibration factors supplied with each secondary reference tape. 4.5 Overwrite. For the two recording modes, the overwrite ratio for the tape shall be less than
24、120 percent of the same ratio for the master standard reference tape. Traceability to the overwrite ratios of the master standard reference tape is provided by calibration factors supplied with each secondary standard reference tape. 4.6 Azimuth. The angular deviation of the recorded flux transition
25、s from a line normal to the reference edge of the tape shall be less than 15 minutes (4.3 milliradians) of arc. 5. Format of Track 5.1 Reference Edge of Tape. The reference edge of the tape is the top edge when viewing the recording side of the tape with the hub end (EOT) of the tape to the observer
26、 s right. 5.2 Calibration Tracks. Calibration tracks are used to establish track position reference values and initial read-back gain values for specific media/head combi- nations. Calibration tracks are not prerecorded on the tape. The drive mechanism that records data on a cartridge for the first
27、time shall write the calibration tracks as described in the following subparagraphs. Refer to Figure 3. 5.2.1 Calibration Track A. Calibration Track A shall be recorded on tapes recorded in either the low density or high density mode. The distance of the centerline of Calibration Track A from the to
28、p edge of the tape shall be 0.143 inch f 0.001 inch (3.63 mm + 0.03 mm). Calibration Track A shall be recorded with contigu- ous repetitions of bit combinations (b, to b,) 01 recording in the direction towards the EOT marker. Calibration Track A shall begin: 30 inches (762 mm) + 4 inches (102 mm) fr
29、om the BOT marker Calibration Track A shall end: 119 inches (3023 mm) + 3 inches (76 mm) from the BOT marker 5.2.2 Calibration Track B. Calibration Track B shall be recorded only on tapes recorded in high- density mode. Calibration Track B shall be located 0.027 inch + 0.001 inch (0.686 mm + 0.03 mm
30、) below Calibration Track A. Calibration Track B shall be recorded with contigu- ous repetitions of bit combinations (b, to b,) 01 recording in the direction towards the EOT marker. Calibration Track B shall begin: 30 inches (762 mm) + 4 inches (102 mm) from the BOT marker Calibration Track B shall
31、end: 119 inches (3023 mm) f 3 inches (76 mm) from the BOT marker 5.2.3 Calibration Track C. Calibration Track C shall be recorded only on tapes recorded in low-density mode. Calibration Track C shall be located 0.214 inch f 0.001 inch (5.44 mm Ifr 0.03 mm) below Calibration Track A. 11 Copyright Ame
32、rican National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- AMEWCANNATIONALSTANDARDX3.181-1990 Calibration Track C shall
33、be recorded with contigu- ous repetitions of bit combinations (b, to b,J 01 recording in the direction towards the BOT marker. Calibration Track C shall begin: 106 inches (2692 mm) f 3 inches (76 mm) from the BOT marker Calibration Track C shall end: 30 inches (762 mm) + 4 inches (102 mm) from the B
34、OT marker 5.2.4 Calibration Track D. Calibration Track D shall be recorded only on tapes recorded in high- density mode. Calibration Track D shall be located 0.214 inch Itr 0.001 inch (5.44 mm f 0.03 mm) below Calibration Track B. Calibration Track D shall be recorded with contigu- ous repetitions o
35、f bit combinations (b, to b,) 01 recording in the direction towards the BOT marker. Calibration Track D shall begin: 106 inches (2692 mm) f 3 inches (76 mm) from the BOT marker Calibration Track D shall end: 30 inches (762 mm) + 4 inches (102 mm) from the BOT marker 5.3 Positions of Track 53.1 Ident
36、ification of Track 5.3.1.1 Forward Tracks. Tracks recorded in the forward direction (from BOT to EOT) are num- bered with even integer values beginning with 0. These tracks are referenced to Calibration Track A and Calibration Track B (high density only). Refer to Figure 4. 5.3.1.2 Reverse Tracks. T
37、racks recorded in the reverse direction (from EOT to BOT) are numbered with odd integer values beginning with 1. These tracks are referenced to Calibration Track C (low density) and Calibration Track D (high density). Refer to Figure 4. 5.3.2 References of Track Base. Data track centerline locations
38、 shall be referenced to the center- line of the respective calibration tracks at an accuracy off 0.0005 inch (k 0.013 mm). Offset dimensions with a negative value indicate that the data track is located below the referenced calibration track. 5.3.3 Number of Tracks low density: 22 tracks numbered 0
39、to 21, inclusive. high density: 48 tracks numbered 0 to 47, inclusive. Refer to Figure 4. 12 5.4 Spacing of Track. The spacing between recorded tracks shall be: low density: 0.0190 inch f 0.0005 inch (0.483 mm + 0.013 mm) high density: 0.0090 inch + 0.0005 inch (0.229 mm f 0.013 mm) Refer to Figure
40、4. 5.5 Width of Track. The width of the recorded track shall be: low density: 0.0180 inch + 0.0005 inch (0.457 mm * 0.013 mm) high density: 0.0085 inch f 0.0005 inch (0.216 mm + 0.013 mm) 6. Format of Tape The recorded area of tape between BOT and EOT shall be partitioned by the following areas (ref
41、er to Figure 5): (1) Calibration areas (2) Guard areas (3) Synchronization areas (4) Dataareas 6.1 Recording Area. The recording area shall be bounded by BOT and EOT. The total length of the recording area shall be at least 625 feet-t 5 feet (190.5 meters f 1.5 meters). Recording of the data tracks
42、takes place in two directions: Forward (BOT to EOT) and reverse (EOT to BOT). 6.2 Calibration Areas. The location and contents of the calibration areas are described in 5.2. 6.3 Forward Guard Areas. Forward guard areas shall not be used to record any data or synchronization pattern. In the forward d
43、irection (BOT to EOT), the guard areas shall begin at the end of the calibration area and shall end: Nominal: 143 inches (3632 mm) from the BOT marker, Minimum: 143 inches (3632 mm) from the BOT marker, Maximum: 155 inches (3937 mm) from the BOT marker. 6.4 Forward Synchronization Areas. In the forw
44、ard direction (BOT to EOT), the forward synchronization areas shall be provided for the purpose of allowing the data recovery circuits to prepare for the subsequent data areas. In the low-density mode, a contiguous repetition of bit combination (b, to b,) 01 may be optionally Copyright American Nati
45、onal Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 22:25:05 MDTNo reproduction or networking permitted without license from IHS -,-,- AMERICAN NATIONAL STANDARD X3.181-1990 recorded immediately before the
46、forward data areas. In the high-density mode, these synchronization areas must be left in a dc-erased state. The forward synchronization areas shall begin at the end of the forward guard areas and shall extend: Nominal: 12 inches (305 mm), Minimum: 12 inches (305 mm), Maximum: 48 inches (1219 mm). 6
47、.5 Forward Data Areas. In the forward direction (BOT to EOT), the data areas shall immediately follow the forward synchronization areas and shall end: Nominal: 611.6 feet (186.4 meters) from the BOT marker, Minimum: 601.6 feet (183.4 meters) from the BOT marker, Maximum: 613.6 feet (187.0 meters) fr
48、om the BOT marker. 6.6 Reverse Synchronization Areas. In the reverse direction (EOT to BOT), the reverse synchronization areas shall be provided for the purpose of allowing the data recovery circuits to prepare for the subsequent data areas. In the low-density mode, a contiguous repetition of bit co
49、mbination (b, to b,) 01 may be optionally recorded immediately before the reverse data areas. In the high-density mode, these synchronization areas must be left in a dc-erased state. The reference point is the end of the forward data areas. The reverse synchronization areas shall begin: Nominal: 12 inches (305 mm) beyond the rever