On 7/7/17 11:10 AM, Chuck Guzis via cctalk wrote:
> I've puzzled over how to do tape flux-transition recording in any > meaningful way. The way JBI did it was to digitize the capstan encoder as a clock reference for tape motion obliquely referenced in http://storageconference.us/2008/presentations/3.Wednesday/5.Bordynuik.pdf -- Thanks to the current administration, all of the NASA Nimbus data reports appear to have dissapeared from the web. mentions in http://www.sciencedirect.com/science/article/pii/S2214242815000212#bb0035 "An examination of these 7-track tapes revealed they were in poor shape. The tapes iron oxide media was falling off the acetate film backing. Fortunately, GSFC had just learned of a Canadian company, JBI Incorporated that had developed a tape recovery process that could read the bits from magnetic tapes with a high degree of certainty. The JBI recovery process involved using specially developed tape drives with 36 magnetoresistive (MR) heads, tape baking (10 h at 175°), bit detection and processing techniques to read the 800 bit-per-inch, 7-track tapes. Based on the original Nimbus HRIR system documentation, GSFC was then able to recover and rescue the observations from thousands of Nimbus HRIR digital data tapes" M. Hobish, D. Gallaher, G. Campbell, W. Meier Dark data rescue: shedding new light on old photons The Earth Observer May–June 2014, 26 (3) (2014), pp. 4-10 for example gsfc.nasa.gov/nimbus/documentation/documents/N7_Recovery_Report_Jul16.doc
