On Sat, 28 Nov 2015, Fred Cisin wrote:
If other errors occur, such as "requested sector
header not found", they may
be misinterpreted by the drive
that's "misinterpreted by CONTROLLER"
although some of the fancier newer drives can also have a problem
So, . . .
WD style: no problem with index pulse timing relative to data
NEC765 style: index pulse is necessary during LLF, but may need to be blocked
during read/write, although a few of the newest drives may not be happy
without index.