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writing garbage when the voltage drops
writing garbage when the voltage drops
Posted Jul 17, 2006 14:29 UTC (Mon) by giraffedata (subscriber, #1954)In reply to: writing garbage when the voltage drops by roelofs
Parent article: Crash-only software: More than meets the eye
OK, I did some calculations. I think the drive needs less than 10 microseconds to finish writing a sector. In that time, it needs up to 1 ampere, and can work with at least 4v out of the 5v power supply. So a 10uF capacitor, which is the size of a pea, should suffice.
The stored energy in the disk probably is relevant too, in that it keeps the disk spinning fast enough for an acceptable write 10 uS after the motor loses power.
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writing garbage when the voltage drops
Posted Jul 25, 2006 3:59 UTC (Tue) by barrygould (guest, #4774) [Link]
I'd expect you want clusters, not sectors, ensured to be written safely.