10 Aug
2007
10 Aug
'07
4:56 p.m.
On 10 Aug 2007 at 11:10, Christian Corti wrote:
But the track-to-track distance is practically the
same, at least I could
perfectly read all my SORD M23 disks in a standard DSHD drive (with tracks
0-2 obviously missing at the beginning). The M23 disks are 100tpi SS MFM,
the drives used are TEAC FD-50C.
Well, let's do the math. At 100 tpi, a track occupies a zone inside
of a band .0100 inch wide. At 96 tpi, a track occupies a band .0104
inch wide. While this may not seem to be a lot, consider that 77
tracks at 100 tpi will occupy a band 0.7700 inches wide, while at 96
tpi, the same number of tracks occupy a band .8021 inches wide. That
means that the 77th track will be 0.0321 inches off--more than 3
tracks' worth at 100 tpi. So, while you may have been able to read
much of the first part of your disks, I suspect that the inner tracks
did not read at all.
Cheers,
Chuck