Date   : Thu, 31 May 1984 05:23:00-EDT
From   : Jerry E. Pournelle <POURNE@Mit-Mc.ARPA>
Subject: Flipping Floppies

??? I don't recall paying a lot of attention  to the problem.  I
still will not flip floppies, but that's me.  I use double sided
anyway.  It happens that in the early days MacLean did some
tests, enough to convince him it was a bad idea, but disk
technology weren't so very good then.
       As to wear, I never saw a disk head worn; but i have
seen them with marks on them, and when marked they gert
extraneous signals and thus lots of soft errors.  The thicker
the media, and the poorer the polish job, on the disk, the
better chance of head marking, I would think; certainly it was
with el cheapo disks (generic disks, no brand names) that I got
the problem, and I have not had it much since switching to
Dysan.
       re Dysan, tony says that they expanded their plant by a
factor of 4 and dropped quality accordingly; and Barry now finds
2 or 3 bad disks per hundrdd in Dysan.