On Fri, 3 Jul 2009 07:24:02 -0400, Klein, Kenneth wrote: > Even more insidious are the methods of reading how strongly the >magnetized bit is positive or negative. If the bit is on, but not as >strongly as others, it might have been off before getting flipped. If >very strongly on it might have been reinforced when the 1 bit was >written to it. It would take several passes of randomized ones and zeros >to fool this technology. > ... or one pass with specialized hardware that overwrites with bits with random amplitude. How consistent is the amplitude in ordinary write amplifiers?
And how repeatable is the longitudinal density? Is there any confidence the overwritten bit occupied the same position as the overwriting bit? -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
