Article on "Keepered" media in Data Storage:
Sept. '96 issue of Data Storage, an industry magazine on technology and manufacture of storage devices, featured “Keepered” media in their technology update section. Researchers at Velocidata (Santa Clara, CA) commented that keepered media can improve the peak-detector channel margin of a Read-Rite inductive thin-film head by as much as 25% and can cut the soft error rate sixfold. William Reed of Velocidata, Inc. added, “Keepered media offers the only known means of improving performance of inductive heads beyond the zero spacing limit.”
According to Dataquest's StorageTrack 1996 Conference (held in Monterey, CA June 26-27, 1996): “Velocidata is a new company with strong roots to the disk component industry. Its products spring from new thinking and new development strategies in head, disk, and read channel technologies. The goal? To provide higher recording densities for rigid disk drives at lower costs. You won't want to miss this exciting breakthrough announcement.” ‘Twice the Data Density at Half the Price' was the title of the presentation given by Dennis R. Hollars, Ph.D, Velocidata's President and Co-Founder.
The article in Data Storage said Reed presented a paper at a recent IEEE meeting on “keepered” media. The article stated that the keepered media that was studied was supplied by Ampex and the University of Minnesota's Center of Micromagnetics and Information Technology (MINT). The article went into some technical details on how the keepered media works, dicussing the concept of the variable reluctance circuit and how the keeper layer acts as a paramagnetic amplifier when its biased with a small magnetic field. In the end, Reed reports keepered media having more than a 6-dB signal-to-noise ratio (SNR) advantage for the densities typical in the thin-film media industry. He added, “Since media SNR is cut by 3 dB for each halving of track width, one could project that keepered media will allow between two and four times the track pitch for similar error rates, depending on the fixed head and preamp noise conditions.” More tracks for a given media area means increased data capacity.
Though this isn't exactly breaking news, I think it's good that we're seeing more discussions in the media industry on "Keepered" media. It's also interesting to note Velocidata's involvement and knowledge on this subject. |
