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IEEE Transactions on Magnetics

Issue 4 • Date July 1981

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Displaying Results 1 - 25 of 34
  • [Front cover and table of contents]

    Publication Year: 1981, Page(s): 0
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    Freely Available from IEEE
  • Chairman's thoughts

    Publication Year: 1981, Page(s): 1371
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    Freely Available from IEEE
  • Effect of flying height variation on offtrack data handling

    Publication Year: 1981, Page(s):1372 - 1375
    Cited by:  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    This study demonstrates the effect of flying height variation on the offtrack data error rate. The experiments completed for this study employ a narrow track Winchester-type Mn-Zn ferrite head and are performed on a single disc spinner in a clean room environment. The variation of the flying height is accomplished by mechanically rippling the disc (artificially warping the disc via specially desig... View full abstract»

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  • Datapoint thin film media

    Publication Year: 1981, Page(s):1376 - 1379
    Cited by:  Papers (10)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB)

    A newly developed thin film disk media is used in a new Datapoint storage subsystem. The magnetic thin film is protected by a newly developed overcoat which has excellent wear resistance characteristics. Magnetic and mechanical data indicates this new thin film media is a significant step forward in advancing magnetic recording technology. View full abstract»

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  • A tester for heads, discs, and read/write channels

    Publication Year: 1981, Page(s):1380 - 1382
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    This paper describes a microcomputer-controlled precision tester designed to evaluate a number of factors crucial in the development of a high performance disc drive. The tester is intended for use in head development, head-to-disc interface characterization, and analog read/write channel development. Issues considered in the design of the tester are the precision of head positioning, the accuracy... View full abstract»

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  • Design considerations for the DASTEK 4830 disk drive

    Publication Year: 1981, Page(s):1383 - 1386
    Cited by:  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    The DASTEK 4830 Disk Drive is designed to provide minicomputer original equipment manufacturers (OEM) with direct access storage having the performance, reliability, and cost/MB characteristics of drives attached to large mainframe computers. This was accomplished by utilizing state-of-the -art technologies in the areas of read/write heads, media, data encoding/decoding, and read/write head positi... View full abstract»

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  • Mechanical and servo design of a 10 inch disk drive

    Publication Year: 1981, Page(s):1387 - 1391
    Cited by:  Papers (2)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (912 KB)

    Design concepts of the mechanical and servo system of a newly-developed compact disk drive are discussed. This new drive features 10 inch diameter disks with a capacity above 400 Mega-bytes. The mechanical structure, with its own closed self-circulating air system , is designed to minimize thermal offtrack and undesired vibration. A new rotary type head actuator is accommodated, and servo system d... View full abstract»

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  • Design of a high performance rotary positioner for a magnetic disk memory

    Publication Year: 1981, Page(s):1392 - 1395
    Cited by:  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    The design described in this paper covers a non-traditional, rotary positioner for a 14 inch, mid-range magnetic disk memory. It was intended to provide high performance and track density while retaining traditional advantages found in rotary positioners such as high reliability, and low cost, power, weight, and size. The paper describes positioner motor architecture and design, head support arm a... View full abstract»

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  • High track density for magnetic disk drives with an "Embedded servo" positioning system

    Publication Year: 1981, Page(s):1396 - 1402
    Cited by:  Papers (2)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    The CII-HB "Embedded servo" original technique for disk drive units (such as the D 160) allows operation at high track densities ( 800 TPI) and fast access time. The overall information needed for head displacement and positioning is provided by the data head itself, without any other transducer. Servo transitions, written between the data sectors, are arranged to provide gain information, track l... View full abstract»

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  • The MD 122 dual 3 Mbyte flexible disk drive

    Publication Year: 1981, Page(s):1403 - 1407
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    The dual 3Mbyte flexible disk drive provides 6 Mbyte of formatted data storage in a compact package designed for in-built use. The two disks may be inserted or removed independently and share a common double ended spindle. A common actuator is used to position the four recording heads. High areal recording density is achieved using advanced technology recording heads and media in association with ... View full abstract»

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  • A 5 megabyte flexible disk

    Publication Year: 1981, Page(s):1408 - 1413
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    The data capacity of a double-sided, 8" diameter flexible disk has been increased from 1.26 megabytes without any substantial enhancement of the magnetic properties. Iron oxide particles of acicularity \sim5:1 and a coercivity of 300 Oe were used; however, the coating thickness was reduced from 100μ" (2.5μm) to 40μ" (1.0μm) to permit a lin... View full abstract»

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  • Read compensation in flexible disk drives

    Publication Year: 1981, Page(s):1414 - 1416
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    The peak shift due to packing density and other effects in flexible disk drives is discussed. Some of the effects merely cause loss of high-frequency components and may be corrected by a suitably designed filter. The design requirements are qualitatively summarized. Comparison with and use with write precompensation is discussed. View full abstract»

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  • Effects of magnetic fields on flexible disk drive performance

    Publication Year: 1981, Page(s):1417 - 1422
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    The read/write heads in flexible disk drives operate in the presence of AC and DC magnetic fields generated by solenoids, motors, recording head erase structures, circuit board components, and external sources such as CRT flyback transformers present in "smart terminals and word processors. Time varying magnetic fields induce signal on the read/write coil and introduce interference. This interferi... View full abstract»

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  • High density magnetic recording on a mini flexible disk drive

    Publication Year: 1981, Page(s):1423 - 1425
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    Small flexible disk drives have developed in a few years from 48 TPI (tracks per inch) single density, 125 kbyte products to 96 TPI double density, two-sided drives with 1 megabyte of capacity. The trend is toward more tracks per inch, with the industry goal currently at 144 TPI. The paper describes the technology that has been developed to make 144 TPI possible. This paper will discuss the evolut... View full abstract»

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  • An ultra-high data rate mass storage system

    Publication Year: 1981, Page(s):1426 - 1431
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    This paper describes the mechanical, electronic, and signal processing capabilities of a special purpose instrumentation mass storage system developed by Bell & Howell Datatape Division. The system is presently operational and encompasses many of the features of computer storage systems including vacuum column tape handling and fast start-stop capability. Throughput rates of up to 450 MBS and ... View full abstract»

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  • A low-cost, high-speed direct access device

    Publication Year: 1981, Page(s):1432 - 1434
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    This paper will deal with the novel approach taken to produce a low-cost, high-capacity, high-speed direct access tape drive. The drive utilizes a removable one-half inch magnetic tape cartridge to compliment industry trends. The device will initially store 80 Mbytes per cartridge with an initial data rate of 500 Kbytes per second. The cartridge format is made up of 615 blocks of 131 Kbytes per se... View full abstract»

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  • Microprocessor controlled tape motion

    Publication Year: 1981, Page(s):1435 - 1437
    Cited by:  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    The capstan control system of a high performance digital tape drive starts and stops tape with accelerations of about 500 g's. A microprocessor based control system is now being implemented on STC's 4500 Tape Systems to attain accurate tape speed control with little high frequency variation. Improvements made possible by the processor include controlling rate of change of motor current and drastic... View full abstract»

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  • The evolution of the high density 1/4" cartridge tape drive

    Publication Year: 1981, Page(s):1438 - 1441
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    A new cartridge tape recorder was designed to provide both a backup for fixed disc drives and an interchangeable media recorder for program loading and data logging. The drive employs a new format designed to use the streaming method of tape handling. Formatted capacities of 10 and 20 megabytes, with nominal backup times in the at-12 minute range, are included in the product family. View full abstract»

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  • Characteristics of a 1-Mbit bubble memory chip

    Publication Year: 1981, Page(s):1442 - 1451
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1256 KB)

    The design and characterization of a 1-Mbit block-replicate (swap) chip organized as 584 loops of 2048 bits each is described. Double period propagation elements are employed in both input and output tracks. All propagation elements employed outside of the storage area have a period in excess of 14 μm to minimize step coverage and conductor induced stress problems. A semi-planar polyimide bas... View full abstract»

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  • Code performance and head/Media interface

    Publication Year: 1981, Page(s):1452 - 1454
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    The limitations of selected run length limited codes relative to their practical recording density at given error rates are examined with a known head/disc system interface. A method is presented for the evaluation of run length limited codes on the basis of error rate as a function of linear density. Experimental measurements of the intrinsic error rate as a function of the linear density were ut... View full abstract»

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  • Fine metal particles having super high coercivity

    Publication Year: 1981, Page(s):1455 - 1458
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    Fine iron-cobalt particles with coercivities as high as 2200 Oe have been obtained. The particles were precipitated from an aqueous solution using sodium borohydride. The coercivity was studied as a function of composition with the maximum coercivity found at 65:35 (Fe:Co ratio). The coercivity was found to arise from two effects. The first is shape anisotropy due to the chain of spheres structure... View full abstract»

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  • Magnetostriction of Fe-Cr-Co alloys

    Publication Year: 1981, Page(s):1459 - 1461
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    The room temperature linear saturation magnetostriction (λs) and saturation magnetization per gram (σs) were measured on polycrystalline samples of alloys containing from 30 wt% to 50 wt% chromium and up to 25 wt% cobalt. The data show that all the λsare positive and that both λsand σsdecrease with increasing chromium ... View full abstract»

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  • Magnetoelastic effects in amorphous Fe40Ni40P14B6alloys

    Publication Year: 1981, Page(s):1462 - 1467
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1544 KB)

    The influence of compressive, tensile, and bending stresses on the magnetization processes, anisotropy energy, and remanence of an as-quenched amorphous Fe40Ni40P14B6ribbon has been studied. The magnetostriction constant has been obtained from the variation of the susceptibility with the applied compressive stress. To better understand the results, domai... View full abstract»

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  • Magnetization reversal mechanism of nickel alumite films

    Publication Year: 1981, Page(s):1468 - 1471
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    The magnetization reversal mechanism of fine cylindrical nickel particles which were electrodeposited in micropores of anodic oxidized aluminum was investigated. The maximum coercive force was observed at the easy direction of magnetization. The anisotropy field, rotational hysteresis loss, and nucleation field were measured by means of a torque magnetometer. Experimental results can be explained ... View full abstract»

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  • Pulse sharpening effects in ferrites

    Publication Year: 1981, Page(s):1472 - 1477
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    Pulse sharpening effects were investigated both experimentally and theoretically in a coaxial transmission line filled with commercially available magnesium manganese ferrite. Measurements of rise-time reduction as a function of pulse voltage, magnetic field bias, and line length were obtained. Output rise times were reduced to values as low as 2.0 ns, with incident rise times as high as 30 ns, op... View full abstract»

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Aims & Scope

IEEE Transactions on Magnetics publishes research in science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage.

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Meet Our Editors

Editor-in-Chief
Pavel Kabos
National Institute of Standards and Technology