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This article details the historical factors that shaped Hollywood’s adoption of magnetic recording during the late 1940s and early 1950s. It draws upon economic theories of technological change, archival correspondence, technical records, analyses of postproduction workflows, and delineations of the structural constraints that limited how the film industry initially wired magnetic media into its production and postproduction stages. In so doing, I explain why the adoption of such a revolutionary recording technology did not initially usher in changes to the industry’s modes of acoustical representation and why these changes instead took place several decades later.

Magnetic tape storage has been used for recording audio, video, instrumentation, and computer data. The medium can record a large amount of data on winding tape and recorded data are reliable and stable. However, the performance of the other storage media, such as optical disc, magnetic disk, and integrated circuit memory, has progressed remarkably, so the advantage of tape storage has decreased. Video tape recorders (VTRs), which are typical systems for magnetic tape storages, are only used for limited purposes now. For these applications, data storage that records instrumentation and computer data on tape retains its advantages and its performance has been improved. We described the history of VTRs at the HISTELCON 2010 and showed that Japan made substantial contributions to their practical use and popularization. In this paper, we compare the vicissitude of magnetic tape data storage with video tape recording.

This study examined the possible influence of audio and video recording of personality assessment measures on anxiety. Undergraduate students in psychology were randomly assigned to Audiotape, Videotape, or Control conditions and given the State-Trait Anxiety Inventory and Rorschach Inkblot Method. A one-way multivariate analysis of variance indicated no significant differences among these conditions on the Spielberger, et al. State-Trait Anxiety Inventory, A-State scale, and five Rorschach measures of situational anxiety. Tape-recording itself did not seem to affect the anxiety indices of these frequently used personality assessments.

The study investigated, in a Nigerian setting, whether the use of videotape recordings is an effective method of teacher education prior to full-time teaching. Two groups of students were used for study. The first group was allowed to practice the skills through micro-teaching with the aid of video recording equipment. The second group practiced their own skills through micro-teaching but without the aid of video recording equipment. At the end of the study it was discovered that the group which used the video recording equipment had more significant progress in the mastery of teaching skills.

A new D-VHS system developed on the basis of the VHS video tape recording format has been developed for recording digital data compatible with digital broadcast systems. The system can handle a variety of digital formats to meet the diverse needs of multimedia applications.

Tape recorders have been shown to affect measures of voice perturbation. Few studies, however, have been conducted to quantitatively justify the use or exclusion of certain types of recorders in voice perturbation studies. This study used sinusoidal and triangular waves and synthesized vowels to compare perturbation measures extracted from directly digitized signals with those recorded and played back through various tape recorders, including 3 models of digital audio tape recorders, 2 models of analog audio cassette tape recorders, and 2 models of video tape recorders. Signal contamination for frequency perturbation values was found to be consistently minimal with digital recorders (percent jitter=0.01%–0.02%), mildly increased with video recorders (0.05%–0.10%), moderately increased with a high-quality analog audio cassette tape recorder (0.15%), and most prominent with a low-quality analog audio cassette tape recorder (0.24%). Recorder effect on amplitude perturbation measures was lowest in digital recorders (percent shimmer = 0.09%–0.20%), mildly to moderately increased in video recorders and a high-quality analog audio cassette tape recorder (0.25%–0.45%), and most prominent in a low-quality analog audio cassette tape recorder (0.98%). The effect of cassette tape material, length of spooled tape, and duration of analysis were also tested and are discussed.

Eating Style of 166 healthy male volunteers (42.7±9.3 yers old) was observed indirectly by Video tape recording (VTR observation) in the search for the characteristic Japanese eating style "HAYAGUI" (eating more rapidly). The meal with same content (757 kcal, 580 g in weight) has taken unrestrainedly in all subjects without changing eating place. Subjects characteristics, meal duration, amount of food, mouthfuls, chews, pause duration, and rates of food consumption per 30 seconds were observed by played back tapes. Six types were classfied in changes in the rate of food consumption, and the six types combined into three eating styles, regardless of similar meal duration. The analysis of variance for hunger, thirst, fullness and other subjective factors rating immediately before and after the meal have shown no signif icances among 3 styles. The most impressive eating style was "Zenhan-type" (25.9% of all subjects), which was characterized by higher rate of food consumption (above 10% of which food per 30 seconds) during the first half and more chewing than other types.

At the dawn of video tape recording in the early 1950s, various recording systems were proposed by American, European and Japanese engineers. Among them, the transverse scanning system was the first practical system to be used. Twenty years later, helical scanning systems gained in popularity and many VTR (video tape recorder) formats began to appear in the broadcasting market. The helical scanning system progressed with the use of tape cassettes, which employed narrower tape, and with the adoption of high density recording technologies. At the end of the 1980s, more digital VTRs began to appear. New systems expanded the uses of VTRs with their many advantages. Over this period, Japan had the largest market share of VTRs in the world. The author reviews the history of broadcast VTRs and traces the organizations and individuals that contributed to the progress of VTRs. The factors that contributed to Japanese manufacturers being a dominant force in the production of practical VTRs are considered.

녹취서 또는 녹취록은 사람의 목소리가 녹음된 녹음매체를 재생하여 청취하면서 녹음매체에 녹음된 사람의 목소리로 전달되는 정보의 내용을 문자로 그대로 옮겨 적은 서면을 말한다. 최근 녹음매체가 공판정에서 증거방법으로서 흔하게 제출됨에 따라 녹취서 역시 녹음매체와 함께, 또는 단독으로 법원에 증거로 제출되고 있다. 이러한 녹취서의 증거법적 성질이나 증거조사 방법은 녹음매체에 비하여 그간 심도 있는 논의가 이루어지지 않았다. 다만 녹취서의 증거능력이나 법적 성질에 관하여 녹음매체가 전문법칙이 적용되는 증거인지 여부와 관계없이 녹취서를 전문증거나 재전문증거·재재전문증거로 볼수 있다는 일부 견해가 있었다. 본논문은 이러한 주장의 이론적 문제점을 지적하고 그 대안으로서 녹취서를 녹음매체에 대한 사본의 성질을 갖는 증거로 보아야 함을 주장하였다. 녹취서에 대한 증거조사는 증거서류 등의 사본에 대한 증거조사 방법과 동일하게 녹취서의 증거능력에 관한 조사와 증거능력이 인정되는 경우 본증으로서의 조사절차로 구별되어 이루어져야 함을 전제로 그 조사 방법을 구체적으로 검토하였다. 이러한 증거조사 절차를 거쳐 공소사실을 인정할 증거가 된 경우, 판결서의 증거 요지란에는 ‘녹취서의 기재’로 표시하면 충분하다는 견해를 밝혔다.

Aggressive track-density scaling in linear magnetic tape recording has been identified as a key means of sustaining capacity scaling. As the reader width decreases, the relative signal contribution of the written track region outside the lateral extent of the reader increases. We model, analyze and quantify side-reading effects of shielded magneto-resistive read heads reading narrow tracks on perpendicular-oriented tape media. We compare results from extended analytical models with experimental data. An understanding of these effects will be important in designing track misregistration budgets and SNR margins for future operating points of parallel-channel tape recording systems.

This chapter provides an overview of the development of video tape recording. The story of video tape recorders really began before the turn of the century with the experiments of Valdemar Poulson. By this time, the relationship between electricity and magnetism was well understood, and the idea of impressing magnetic pulses on a moving magnetic medium was sufficiently advanced in 1900 to justify a US patent on Poulson's apparatus, the telegraphone. The medium was magnetic wire rather than tape, was without any form of recording bias, and had scant means of signal amplification; also, the reproduced sound signal was low, noisy, nonlinear, and lacking in frequency response. These problems of tape and record or replay head performance are ones that have continually recurred throughout the history of sound and vision tape recording. The magnetic wire gave way to steel tape 6 mm wide travelling at 1.5 meters per second, and performance became comparable with the contemporary disc recording system.

Since the year 2000, a total of seven trips have been made to India with the specific objective of obtaining sound recordings of different species and especially of soundscapes in a variety of places representative of the diversity of India’s ecosystems. Special attention was paid to nocturnal recordings during dusk-dawn periods. Since the beginning of the project, one of the main objectives has been the use of the recordings as an educational resource, in order to divulge and increase awareness regarding India’s natural patrimony. A selection of recordings are presented using QR code format to give an idea of the biodiversity reflected by the soundscapes. In January 2017 continuous recordings were made using Wildlife Acoustics SM4 recorders at a jungle farm adjacent to the Mudumalai Tiger Reserve (Tamil Nadu). These continuous recordings have allowed us to obtain initial acoustic indices that reflect the relationship between biophony, anthrophony and biodiversity levels, as well as a first attempt at automated detection of specific vocalizations, such as the alarm calls of Cheetal (Axis axis) and Sambar (Rusa unicolor). Since the year 2000, a total of seven trips have been made to India with the specific objective of obtaining sound recordings of different species and especially of soundscapes in a variety of places representative of the diversity of India’s ecosystems. Special attention was paid to nocturnal recordings during dusk-dawn periods. Since the beginning of the project, one of the main objectives has been the use of the recordings as an educational resource, in order to divulge and increase awareness regarding India’s natural patrimony. A selection of recordings are presented using QR code format to give an idea of the biodiversity reflected by the soundscapes. In January 2017 continuous recordings were made using Wildlife Acoustics SM4 recorders at a jungle farm adjacent to the Mudumalai Tiger Reserve (Tamil Nadu). These continuous recordings have allowed us to obtain initial acoustic indices that reflect the relationship between biophony, anthrophony and biodiversity levels, as well as a first attempt at automated detection of specific vocalizations, such as the alarm calls of Cheetal (Axis axis) and Sambar (Rusa unicolor). Since the year 2000, a total of seven trips have been made to India with the specific objective of obtaining sound recordings of different species and especially of soundscapes in a variety of places representative of the diversity of India’s ecosystems. Special attention was paid to nocturnal recordings during dusk-dawn periods. Since the beginning of the project, one of the main objectives has been the use of the recordings as an educational resource, in order to divulge and increase awareness regarding India’s natural patrimony. A selection of recordings are presented using QR code format to give an idea of the biodiversity reflected by the soundscapes. In January 2017 continuous recordings were made using Wildlife Acoustics SM4 recorders at a jungle farm adjacent to the Mudumalai Tiger Reserve (Tamil Nadu). These continuous recordings have allowed us to obtain initial acoustic indices that reflect the relationship between biophony, anthrophony and biodiversity levels, as well as a first attempt at automated detection of specific vocalizations, such as the alarm calls of Cheetal (Axis axis) and Sambar (Rusa unicolor).

Since the year 2000, a total of seven trips have been made to India with the specific objective of obtaining sound recordings of different species and especially of soundscapes in a variety of places representative of the diversity of India’s ecosystems. Special attention was paid to nocturnal recordings during dusk-dawn periods. Since the beginning of the project, one of the main objectives has been the use of the recordings as an educational resource, in order to divulge and increase awareness regarding India’s natural patrimony. A selection of recordings are presented using QR code format to give an idea of the biodiversity reflected by the soundscapes. In January 2017 continuous recordings were made using Wildlife Acoustics SM4 recorders at a jungle farm adjacent to the Mudumalai Tiger Reserve (Tamil Nadu). These continuous recordings have allowed us to obtain initial acoustic indices that reflect the relationship between biophony, anthrophony and biodiversity levels, as well as a first attempt at automated detection of specific vocalizations, such as the alarm calls of Cheetal (Axis axis) and Sambar (Rusa unicolor).

The February 4, 1968 UFO sighting at Redlands, CA was accompanied by an intense, distinctive sound that was recorded as a background sound on a magnetic tape recording being made by Reverend Julian Vigh at the Bethel Christian Church. A rescue Emergency Vehicle (EV), with its siren operating, happened to be deployed in Redlands at the time of the UFO sightings. An informal inquiry by several Redlands University professors attributed the background sound on the Vigh recording to the EV siren. Subsequently, I performed independent comprehensive detailed sonic analyses of the tape background sound and the EV siren, and documented these analyses in a 1969 report intended for inclusion as an independent technical appendix in a book on the Redlands UFO sightings then in preparation by authors David Branch and Robert Klinn. This book was never completed and published. The independent technical appendix is released and published here for the first time. Detailed tape analyses revealed and quantified a number of sonic anomalies. Present day concluding comments are offered that place these anomalies in the context of other investigative reports of the Redlands UFO sightings that appeared in the press subsequent to the writing of the appendix in 1969.

A tape recording head in which reading and writing functions are provided by separate modules is presented. The read-only module may be fabricated with a thinner gap than conventional read-write modules. This was shown to provide >; 40% less gap recession in a controlled wear test. Writing modules are configured to contact tape in one tape motion direction only, thus reducing the wear duty cycle twofold. Modeling indicates that broadband signal-to-noise ratio decline due to wear can be up to several dB less for the separated reading-writing head, which therefore may enable advances in linear and thus areal density.

Since the Þrst experiments on magnetic recording by Valdemar Poulsen in 1898 the use of this technology has grown tremendously and magnetic storage is used in almost every home in the world. A special challenge was the recording of video signals which need a high bandwidth. In the 1950s, television broadcasts had started which created a need for storage in the broadcast world. The Þrst broadcast recorder was the Quadruplex from Ampex in 1956. Later solutions were found for application in the consumer market. Better mechanics, magnetic tapes and recording heads allowed the mass production of a cheap consumer recorder. The size and weight decreased tremendously and portable camcorders are very common. Recording of broadcasts, video rental and home movies are now very popular. The factors which contributed to the maturing of this technology will be reviewed in this paper.

Local microscopic particle density variation stemming from packing density far below unity is one of the important aspects of digital tape recording. In this paper, we present a modeling methodology for simulating realistic particle packing in particulate tape media. The packing algorithm is able to generate randomly dispersed tape particles with packing density as high as 34%-40% and user-defined parameters such as easy axes orientation, aspect ratio variation, size distribution, etc. Micromagnetic modeling of recording characteristics have also been conducted to study the impact of various aspects of packing.

We present a planar thin-film servo write head for writing timing-based servo patterns. The planar head operates at low current ( ~ 100 mA) with nanosecond switching times. The planar head can handle dc current, enabling trailing-edge writing. Magnetic force microscopy measurements of the transitions written by the planar head and a conventional commercial servo write head on longitudinal metal particle and nonoriented barium ferrite media were made to assess the quality of the written transitions. The transition response width PW50 is found to be independent of the tape velocity during write for the planar head. For the conventional head, PW50 is larger and increases with the tape write velocity. The reduced PW50 results in larger readback signal amplitude and hence an improved track-follow performance. The faster switching capability of the planar head enables formatting at higher tape velocity.

We examine the issue of scaling magnetic tape-recording to higher areal densities, focusing on the challenges of achieving 100 Gb/in2 in the linear tape format. The current highest achieved areal density demonstrations of 6.7 Gb/in2 in the linear tape and 23.0 Gb/in2 in the helical scan format provide a reference for this assessment. We argue that controlling the head-tape interaction is key to achieving high linear density, whereas track-following and reel-to-reel servomechanisms as well as transverse dimensional stability are key for achieving high track density. We envision that advancements in media, data-detection techniques, reel-to-reel control, and lateral motion control will enable much higher areal densities. An achievable goal is a linear density of 800 Kb/in and a track pitch of 0.2 µm, resulting in an areal density of 100 Gb/in2.

This paper reports on a corrosion-resistant spin-valve head (Ta/NiFe/CoNiFe/CuAu/CoNiFe/PtMn/Ta) for a tape recording system. The spin-valve film has a +0.4 V higher electrochemical potential than the conventional spin-valve film (Ta/NiFe/CoFe/Cu/CoFe/PtMn/Ta). The spin-valve head with CoNiFe magnetic layer and CuAu spacer exhibits good corrosion resistance. An investigation of the recording characteristics of the corrosion-resistant spin-valve head with metal evaporated (ME) tapes showed that: 1) the spin-valve head had about 64% of the output voltage of an isolated pulse of the conventional spin-valve head; 2) the carrier-to-media noise (C/N/sub media/) ratio at a wavelength of 0.4 /spl mu/m of the spin-valve head is the same as that of the conventional spin-valve head; and 3) the C/N/sub media/ ratio of thin ME tape with magnetic layer 33 nm thick was maximized at around M/sub r/t=10 mA, where M/sub r/ is the remanent magnetization and t is the magnetic layer thickness. These results indicate that the corrosion-resistant spin-valve head (Ta/NiFe/CoNiFe/CuAu/CoNiFe/PtMn/Ta) for a tape recording system provides high recording density.

Magnetic tape systems provide high reliability storage at a low total cost of ownership and are well suited for the long term storage of less frequently accessed data. The current explosive growth rate of digital data is driving demand for cost effective storage technologies and has resulted in a renaissance in applications for tape systems. Current state of the art tape systems operate with areal densities up to ∼6 Gb/in2 and provide cartridge capacities up to 10TB. The future success of tape systems depends on continued areal density and capacity scaling to maintain or increase the current cost advantage of tape over competing technologies. In this work we describe a set of technologies that enable the scaling of tape recording to areal densities of 100 Gb/in2 and beyond.

In this study, the signal-to-noise ratio (SNR) performances of longitudinally, randomly, and perpendicularly oriented particles, based on hexagonal barium ferrite (h-BaFe) platelets with an average volume of 2400 nm 3 have been studied as a function of the recording head to media distance by numerical micromagnetic simulations. The distances from the write head to media and from the read head to media were varied independently. For a fixed read distance and varied writing distances, the SNR was decreasing in larger write distance. An optimum write distance of 40 and 50 nm was found for the longitudinally oriented media and the perpendicularly oriented media, respectively. The optimum write distance for longitudinally oriented media, 40 nm, resulted in the local minimum SNR for the perpendicularly oriented media. In most write distances the perpendicularly oriented media show the outstanding best performance, but near the write distance of 40 nm the longitudinally oriented media work as good as the perpendicularly oriented media. In a fixed write distance with various read distances, the SNR was almost constant in each media whereas the average signal amplitude was exponentially decayed in larger read head to media distance. The best SNR was found in the perpendicularly oriented media at write head to media distance d write =20 nm and read head to media distance d read =40 nm. The best SNR value is 11.9 and 24.4 dB in time domain and frequency domain, respectively.

Discusses magnetic tape recording for HDTV studios and describes DCT (discrete cosine transform) codecs for digital video recording. Block diagrams of data reduction systems are presented, and the use of spectral analysis ahead of variable length coding is described. Advantages are suggested over normal PCM and results of multiple copying are reported, showing both subjective tests and chromakey tests. Data compression by a factor of 2 to 3 yields acceptable quality.

A major cause of magnetic spacing losses in data tape systems is pole tip recession (PTR). This study is an investigation of PTR in a linear data tape recording system and identification of the mechanisms responsible for these effects, but the results have implications for any head where the tape bearing surface is Al2O3/TiC, AlTiC. Tape cycling experiments were performed using the linear tape open system as the experimental platform with metal particle tape. All experiments were conducted within a matrix of pressure and humidity, which encompassed the system operating extremes. Atomic force microscopy was used to analyze the surface topography of the heads. Auger electron spectroscopy and x-ray photoelectron spectroscopy were employed to analyze the chemical changes on the surface of the heads and tapes. Environment was found to have a significant influence on the head/tape interface. Head wear and PTR was highest at high temperature and humidity. Water vapor was found to transform the surface layers on the TiC grains in the tape-bearing surface to TiO2. This process results in the production of TiO2 fragments that become trapped in the recessed pole tip region, acting as three-body abrasive particles. The TiO2 present on the TiC grains and on the surface of heads increases with the water content after cycling against tapes. The hypothesis is supported by the presence of Ti on the poles.

Magnetic tape recording is one of the oldest data storage technologies, and it is still used today due to its low cost and long data storage life. Magnetic tape recording is a contact recording technology, where a thin flexible magnetic tape medium is pulled across an Al2O3/TiC (AlTiC) recording head surface at a high velocity while in direct physical contact with each other. As a result, one of the inherent problems faced in magnetic tape recording systems is an increase in the magnetic spacing over time with prolonged usage, due to continuous wear of the tape bearing head surface, which in turn leads to a deterioration of the magnetic readback signal [1]. The increase in the magnetic spacing at the head-tape interface can be due to several factors, such as pole tip recession (PTR), accumulation of wear debris on the head and surface roughness of the head and tape medium. Out of these factors, PTR is a major contributor to the magnetic spacing loss, due to a higher rate of wear of the softer magnetic read and write poles at the head-tape interface [2].Copyright © 2014 by ASME

A hardware implementation of the Eureka-standard data reduction codec is described. The algorithm employed is an adaptive intrafield/intraframe discrete cosine transform with adaptive quantisation and variable-length coding. Interframe editing, multiple copying and rapid search are guaranteed by the special codec architecture.

The tribology of the head to tape interface (HTI) of two linear tape recording systems, Travan™ NS20 and OnStream ADR™ are studied from the viewpoint of pole tip recession (PTR) and stain transferred from the tape. Heads tested in humid conditions (60% RH) show the highest PTR increase with deep and wide grooves forming on the pole surface, presumably ploughed by large fragments pulled out from the ceramic in a single catastrophic event. Smaller pullouts are likely to sediment within the recessed poles and increase the PTR acting as three-body abrasive particles. Both the recession of the TiC phase in respect to the Al 2 O 3 phase over the Al 2 O 3 –TiC ceramic used as tape bearing surface (TBS) and the detection of Ti over the pole tip area by Auger electron spectroscopy (AES) identify the pullouts as being TiC fragments. XPS analysis shows a partial oxidation of the TiC phase, however, too superficial to account for the TiC pullout. Stain is detected on the heads either as discrete or restrained deposits (at high humidity) or as a continuous film, forming preferentially over the pole tip surface. The transfer films arises from the recessed pole edge at low humidity (10% RH) and centre at higher humidity (>35% RH), then gradually covers the remaining pole surface within 100 h in both cases. Finally, a preferential transfer is observed over the pole tip area and the TiC phase of the TBS surface, and may relate to their metal-like nature, as opposed to the insulating nature of the other materials.

The Pole Tip Recession (PTR) and transferred material (stain) are major causes of magnetic spacing losses in magnetic recording system. The recorded signal amplitude is only independent of the data being read if the spacing is zero. Thus, the level and more specifically the variation in head media spacing with device life must be a minimum to maximise signal output and minimised errors. It was the purpose of this research to isolate and identify the mechanisms responsible for pole tip recession using the Linear Tape Open format as an experimental platform, but the results have implications for any head where the tape-bearing surface is Al2O3/TiC (AlTiC). All experiments were conducted within a matrix of pressure and humidity, which encompassed the system operating extremes. Atomic force microscopy (AFM) was used to analyse the surface topography of the heads and monitor the development of PTR after 100, 1000 and 5000 passes of tape. Auger electron spectroscopy (AES) was employed to analyse the chemical changes on the surface of the heads after 5000 passes of tape and X-ray Photoelectron Spectroscopy (XPS) was used to identify the chemical changes that occurred at the head surfaces. Optical Microscopy was employed to identify the head surface changes before and after wear. Environment was found to have a significant influence on the head/tape interface. Head wear and PTR were highest at high temperature and humidity. Wear between the head and tape was found to transform the surface layers on the TiC grains in the tape-bearing surface to TiO2. This process results in the production of TiO2 fragments that become trapped in the recessed pole tip region, acting as three-body abrasive particles. The presence of Ti on the surface of head thin film region confirmed that the three-body particles originated from the head AlTiC ceramic. The TiO2 (thickness and possible areal coverage) increased with the water content increase, wear of head increased in the high water content condition.

In this paper, we report the properties of Co/Cr and CoCrPt/CoCrMn thin films grown by oblique sputtering onto polymer substrates. It is observed that in both cases, the underlayers promote the formation of HCP-structure of the magnetic layers, which results in a high magnetic anisotropy of the films consequently, high coercivities of 200 and 300 kA/m are obtained in the 20nm Co/180nm Cr and 30nm CoCrPt/50nm CoCrMn films, respectively. However, in the case of Co/Cr film, Co grains are relatively large and elongated following the transverse direction while in the case of CoCrPt/CoCrMn film, a tiny columnar structure inclined toward the incident direction is observed. This fact results in a different magnetic behavior of these films.

Digital tape recording systems show the same trend as hard-disk drives: a large increase of storage density with time. The use of advanced media and highly sensitive thin-film heads with magnetoresistive (MR) readout will increase the storage density dramatically. Key improvements are narrower tracks, more sensitive MR elements attained by applying the giant magnetoresistance effect, high-saturation flux density pole materials, advanced metal powder tape, intimate head-to-tape contact, and accurate tracking. By increasing the number of channels in the multitrack thin-film head, high data rates can be obtained as well. The basics of digital magnetic recording are discussed and a short historical overview is given of the Philips activities on thin-film heads for tape recording. An outlook on future improvements is given.

The Self-Initiated-Tape-Recording Method (SITRM) is a qualitative data collection procedure that places few restrictions on the behavior of participants and thereby permits the recording of participants’ perceptions of freely chosen, spontaneous acts. The SITRM was developed to access participants’ “immediately recalled experience” of various events or situations in everyday life. Participants using the SITRM cany a mini tape-recorder and report their experiences of situations or events directly to the tape- recorder. Specific procedures for utilizing the SITRM are described in this paper. Further, findings of three studies examining the effectiveness of the SITRM are reported.

IBM thin-film tape heads have evolved from the ferrite-based heads first used in the IBM Model 3480 Tape Drive to the hard-disk-drive (HDD) technology flat-profile heads used in IBM Linear Tape-Open® (LTO®) products. This paper describes that transition and discusses the flat tape head manufacturing processes, drive implementation, performance, and outlook. Thin-film head technology for hard-disk drives was first used in tape heads in the early 1990s, when IBM built quarter-inch cartridge head images on HDD-type wafers. This was a springboard for the next step, flat-lapped tape heads, which use not only HDD wafers, but also HDD post-wafer machining technologies. With the emergence of LTO, flat heads entered mainstream tape head production in IBM. These have proven to have high performance and durability.

Tape cycling experiments were performed with a Travan™ linear tape system using metal particle (MP) media. The effects of various environmental conditions, particularly water content, on the tribology of the head/tape interface were studied. Auger electron spectroscopy (AES) and atomic force microscopy (AFM) were used to characterise the chemical and physical surface changes that occurred at the head surfaces. Transfer of material from the media to the head was observed at each condition. X-ray photoelectron spectroscopy (XPS) was used to identify the chemical changes that occurred at the media surface. This showed that in all areas of the tape, the amount of detected iron had increased, while the nitrogen (binder indicator) signal had decreased. Significant differences in elemental concentrations were also detected between areas directly in contact with the cartridge drive belt compared to those not in contact. Pole tip recession (PTR) was around 50–65 nm after 5000 passes, but increased at the higher water contents. AES results showed that stain is a function of water content, not relative humidity. It was noted that a larger ceramic grain size seemed to increase PTR.

A new dynamic modelling of the tape vibration in a magnetic recording system is proposed by the concept that the length of the magnetic tape is divided into the entrance, head–tape coupling and exit regions. The main contribution of this paper is that the curvature effect of circular arc of the magnetic head is introduced in the dynamic formulation of the head–tape coupling region. The new separation spacing between the head and tape is defined. The steady state separation spacing and pressure distribution of foil film are compared for various curvatures of the magnetic head shape.

This chapter explores the future scaling potential of magnetic tape technology based on low-cost particulate media. We first discuss the state of the art of particulate media. Moreover, we review the achievements and the technologies behind the recent 29.5 Gbit/in 2 areal density demonstration using low-cost particulate BaFe media. Finally, we examine the potential for further scaling, posing the questions: “Can magnetic tape be scaled to 100 Gbit/in 2 ?” and “What technologies are required to do so?” We conclude that using a combination of the technologies described in this chapter, the roughly 50 Gbit/in 2 areal density predicted by the INSIC roadmap to be required for a 128-TB cartridge appears achievable. Pushing these technologies further, a linear density of 650-800 kbit/in and a track pitch in the range of 0.165-0.2 μm may also be feasible, leading to an achievable areal density of 100 Gbit/in 2 .

The mechanics and tribology of a flat head for high-speed, contact tape recording is presented. Experiments performed on a “row-bar” of thin-film disk heads where the tape is wrapped only on the edge opposite to the heads showed very stable contact for a wide range of tape speeds and very low wear. A model of the interface showed that a self-acting, subambient air bearing forms near the leading wrapped corner. This suction is caused by the expansion of air into the diverging gap on the upstream side of the head-tape interface, which is unique to this wrap geometry, and it is responsible for the stability and low contact pressures. A bidirectional version of a flat head geometry is analyzed via modeling and suggestions are made for that design. This work also showed strong evidence of a threshold of contact pressure below which wear becomes negligible.

Conventional helical-scan magnetic recording requires precise head tracking, precise tape path and accurate servo control. We have developed a magnetic tape recording system based on a new concept, the ‘non-tracking method’, which requires less accuracy. By combining double density track scanning and data rearrangement through a memory device, all data can be reproduced in correct order without precise head tracking. When the track pitch is 9.8 μm, the non-tracking method expands the tolerance on head tracking to ±100 μm, while the head tracking tolerance of ±5 μm is needed in conventional recording. Using the non-tracking method, a newly developed rotary head drum loading system called ‘non-loading’ and also a newly developed metal-evaporated tape, we have developed an extremely high density digital audio tape recording system, including a stamp-sized tape cassette and a miniature digital audio recorder. Two hours stereo digital recording is achieved with the small cassette.

The SSQ-1 Digital Tape Recording Horizontal Pendulum Tiltmeter is an instrument of high sensitivity to detect the changes of ground tilt. It uses a quartz horizontal pendulum held by Zollner bifilar suspension to sense vertical displacement, the eddy-current transducer on the pendulum converts its displacements into electric signals. Then a microcomputer is used for data acquisition and printing as well as digit tape recording. And at the same time, a filtering pen recorder is used for visible recording. The scale value of the instrument is calibrated by computer using the known tilt angle of the bulging plate — mercury cup. The scale value is 0.3–0.5 m(″)/mV.

A recently developed, advanced multi-track tape head for operation in a next generation, high performance tape drive is described. This head features full thin film write elements with high moment, cobalt-based pole materials for recording on high coercivity metal particle (MP) tape, together with narrow track, shielded, dual-stripe magnetoresistive (DSMR) read elements. This presentation will discuss the global design philosophy of the head with particular attention to the design and recording performance of the read and write elements in a tape environment. The bead is capable of recording 288 tracks on half-inch, MP tape of 1625-1850 Oe coercivity at a recording density of 65 kfci. The system operates with 16 parallel data channels and includes full multi-element active track following servo. The head can be used in a full start-stop mode and read verify on the fly (read-while-write) bi-directional operating modes.

In this paper we present results on the fabrication and testing of thin film tape recording heads using high moment FeAlN pole materials (4/spl pi/M/sub s/=20 kGauss). These heads are of the type used in quarter inch cartridge (QIC) tape drives, with a record gap dimension of 1.9 /spl mu/m and a written track-width of 33 /spl mu/m. The pole thicknesses ranged from 4 to 4.5 /spl mu/m with a 14 turn coil. The FeAlN pole material delivers sufficient field to the media surface to saturate 1.5 /spl mu/m thick Ba-Ferrite media (H/sub c/=1500 Oe). In comparisons to a head of identical design with CoZrTa poles, the FeAlN poles were able to deliver more flux to the media because of a higher head saturation onset current.