On Wed, 12 Aug 2015 13:21:45 -0500, Joel Ewing wrote:
> My strong impression was that the erased IBG between physical blocks was a
>requirement for proper sensing of beginning of a block. The requirement
>that some 32-byte increments must be left unused for IBGs indicates
>these 32-byte groupings do not play the same role as fixed data blocks
>in FBA architecture devices.
>
"left unused"? or marked as unused? (although this may be a distinction
without a difference). And it may depend on choice of encoding technique:
NRZI? MFM? GCR: (0,2) RLL? The last is interesting because it has 17
encodings available to represent a 4-bit nybble. Some systems use the
extra code point to signal control information, which might be a logical IBG.
https://en.wikipedia.org/wiki/Run-length_limited#GCR:_.280.2C2.29_RLL
-- gil
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