Laser Guided Magnetic Recording.This article is the first in a two-part series. The second part will appear in the August issue of CTR See click-through rate. . 1899 marked the beginning of the first revolution in magnetic recording technology as Valdemar Poulsen Valdemar Poulsen (November 23, 1869, in Copenhagen – July 23, 1942) was a Danish engineer. He developed a magnetic wire recorder in 1899. The magnetic recording was demonstrated in principle as early as 1898 by Valdemar Poulsen in his Telegraphone. of Denmark invented and patented the first true magnetic recorder n. 1. A device for making records (of sound, data, etc.) on magnetic media such as magnetic tape or wire. Noun 1. magnetic recorder - recorder consisting of equipment for making records on magnetic media , the Telegraphone. Magnetic Recording, although dramatically advanced since its invention by Poulsen, remains the single most enabling technology for digital data recording systems. As we celebrate 100 years of magnetic recording development and advancement, the appropriate background is set to highlight a truly revolutionary advancement, Quantum's Laser Guided Magnetic Recording (LGMR (Laser Guided Magnetic Recording) A SuperDLT technology developed by Quantum that uses both sides of the tape. The recording side contains no servo tracks and is completely filled with data. ). For the first time in tape history, laser technology has been joined with magnetic to form a single system that greatly enhances the recording capability of magnetic tape media. This breakthrough technological advancement takes full advantage of refinements in optical and magnetic technologies, expands the overall capabilities of each, and offers a new standard in digital magnetic recording. Although magnetic recording was first introduced into the fledgling "computer industry" of the 1950s, it was not until the 1980s that the magnetic recording of digital data began to significantly advance its capabilities. A major milestone in the advancement of magnetic recording for data storage came in 1989 with the introduction of the first DLTtape drive. These drives were a new class of compact, high capacity, high performance linear tape storage products designed specifically to meet the needs for escalating capacity and reliability. They provided the first true option to consumer-based helical scan A tape recording method that uses a spinning read/write head and diagonal tracks. Although it uses a rather complex transport mechanism, it is very gentle on the tape. After the cassette is inserted into the drive, the tape is pulled out and wrapped around the read/write head. technology. Since its introduction, Quantum's DLTtape technology has advanced the state of the art in magnetic tape performance with a number of technology firsts for linear tape systems. These firsts include Metal Particle Tape, Flash Code Updates, Fast Data Access of Tape Directory, utilization of Data Compression data compression Process of reducing the amount of data needed for storage or transmission of a given piece of information (text, graphics, video, sound, etc.), typically by use of encoding techniques. and Compaction, Double Coated Media, and Symmetric Phase Recording Tape recording technology developed by Quantum Corporation packs data across a tape's recording surface by writing adjacent tracks in a herringbone pattern: track 0 = \\\\\, track 1 = /////, track 2 = \\\\\, track 3 = /////, etc. . With these technological inventions and innovations, Quantum engineers revolutionized the magnetic data recording industry and created the de facto standard Hardware or software that is widely used, but not endorsed by a standards organization. Contrast with de jure standard. de facto standard - A widespread consensus on a particular product or protocol which has not been ratified by any official standards body, such as ISO, for reliable, high-performance data backup and archive for mid-range servers. Quantum's next generation storage system, Super DLTtape technology, builds on this legacy by providing a reliable, robust mid-range tape capacity and performance from the first product generation through a multi-generation roadmap. Super DLTtape Technology offers the next substantial advancement in three critical attributes of magnetic recording. These progressions in technology offer higher bit density, a far greater surface area than other storage mediums, and, more importantly, an increase in order of magnitude A change in quantity or volume as measured by the decimal point. For example, from tens to hundreds is one order of magnitude. Tens to thousands is two orders of magnitude; tens to millions is three orders of magnitude, etc. in track density. These three factors contribute to Super DLTtape Technology's high cartridge capacity and performance potentials, once again raising the standards bar in magnetic data recording. The cornerstone of the Super DLTtape Technology platform is its use of Laser Guided Magnetic Recording (LGMR). This unique technology application will produce an advanced scalable platform designed to meet an extraordinary range of storage requirements. LGMR Technology LGMR ensures higher cartridge capacities by allowing for the substantial increase in the number of recording tracks and recording density on the data surface of the media by servoing from optical targets on the media's back side. In the development of Super DLTtape Technology, design engineers aimed to advance the capabilities of many of the critical attributes of magnetic recording. By using enhancements in tape formulations, head designs, and recording channel technologies, they were able to achieve increased recording densities and a substantial increase in the number of tracks available for recording. However, by increasing the number of tracks, more advanced servo An electromechanical device that uses feedback to provide precise starts and stops for such functions as the motors on a tape drive or the moving of an access arm on a disk. techniques were required to ensure efficiency. It was clear that all traditional magnetic tape servo methods had a fundamental problem: they all used a portion of the recording surface to store the servo track information. The engineers created a design breakthrough: they designed and developed technology to take advantage of the previously un used backside of the media by laser-etching optically read servo tracks on a specially formulated back coating. This design innovation, the placing of magnetic data tracks on one side of the tape and indelible optical guidance tracks on the other, provides increased storage space on the magnetic side of the media. By introducing these Quantum-refined optical tracking technologies, the servo tracking capabilities of traditional magnetic systems have been greatly improved. The result is the foundation of LGMR. LGMR offers substantial benefits and enhancements to magnetic recording, including: * Greater performance and capacity: 100 % of the data-bearing side of the media is used for data recording. 100 % of the heads are used for the data recording. * Greater reliability: The laser servo tracks are indelible--the servo information cannot be magnetically erased. Indelible servo information removes the need for magnetic pre-formatting tapes. Optical Laser Tracking System utilizes a three-beam hologram See holographic storage. configuration for exact tracking. Non-contact writing and reading of optical tracks greatly reduces media wear. * Greater potential for future scalability: LGMR is currently utilizing a fraction of the potential capability of optical tracking, ensuring continued compatible advancement in the future. Four key technologies contribute to the revolutionary capacity and performance that LGMR brings to Super DLTtape Technology. These Quantum patented technologies are: * Pivoting Optical Servo (POS (1) See point of sale and packet over SONET. (2) "Parent over shoulder." See digispeak. POS - point of sale ) * Magneto-Resistive Cluster Heads (MRC See Maximum return criterion. ) * A New, High-Efficiency PRML (Partial Response Maximum Likelihood) A technique used to differentiate a valid signal from noise by measuring the rate of change at various intervals of the rising waveform. Channel * Advanced Metal Powder Media (AMP) Pivoting Optical Servo (POS) The Pivoting Optical Servo is at the core of LGMR technology. It offers a combination of the best of optical and magnetic technologies. POS is an optically assisted servo system, which combines high-density magnetic read/write data recording with laser servo guiding. Designed for high duty cycle applications, the POS has a much lower sensitivity to outside influences, which allows the Super DLTtape system to achieve a track count with an order of magnitude increase over current DLTtape products. The POS system decreases manufacturing costs and increases user convenience by eliminating the need- for preformatting the tape. Additionally, customers gain 10 to 20 percent more capacity that is lost with traditional magnetic servo products. Super DLTtape uses a full 100 percent of the recording surface for actual data recording by using the optical servo on the unused backside of the media. This offers an improvement over traditional magnetic servo tape products, in which a portion of the front side of the media must be reserved for servo activities. As the media moves through the POS, the optical tracking laser follows along on the backside of the media, tracking the embedded Inserted into. See embedded system. optical targets. The POS assembly pivots around a single mounting point to keep the magnetic read/write heads A device that reads (senses) and writes (records) data on a magnetic disk or tape. For writing, the surface of the disk or tape is moved past the read/write head. By discharging electrical impulses at the appropriate times, bits are recorded as tiny, magnetized spots of positive or aligned with the optical tracks and reading data from or writing data to the tape. George Saliba George Saliba has been Professor of Arabic and Islamic Science at the Department of Middle East and Asian Languages and Cultures, Columbia University, New York, United States, since 1979. is the vice president of the Advanced Products Group and DSSG DSSG Defense Science Study Group DSSG DISN (Defense Information Systems Network) Support Services-Global DSSG Distributed Storage Services Group (Indiana University) DSSG Desktop Support Services Group chief technical officer at Quantum (Shrewsbury, MA). |
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