29 Dec
2010
29 Dec
'10
2:26 p.m.
On 29 Dec 2010 at 18:45, Tony Duell wrote:
Are you perhaps thinking of the Memorex 651 disks with outer-edge
holes and a large "notch" along one side? Those were 64 cylinders,
32-hard-sector, spinning at 375 RPM. Same FM data rate, though (250
Kbit/sec) as the Shugart-style 8" floppies.
I think some of the early IBM models (did they ever get into
production?) used 8 sector holes along the outer edge.
--Chuck
ISTR: the
8" drives at least as used in tandy computers formatted
out to 77 tracks....
Were there 8" drives that had something other than 77 cylinders?
Perhaps the very early IBM ones with the index holes around the
outside edge? Certainly all the ones I've come across were 77
cylinders.