27 May
2012
27 May
'12
9:03 p.m.
Fortunately, in NZ we'd pretty much never see 40
degrees C, though in roof
spaces etc I'm sure it can reach and exceed that.
Yes, indeed it does. I had a stash of Dick Smith System 80 disks stored up
there (in a roof space under corragated iron) for a few years in the 1990s.
Bad idea. Almost every one was unusable due to media damage when I tested
them after moving house. I recall it did get pretty hot in that roof space.
Others stored in a cool dry place (my university office for example) were
fine.
Tez (also in New Zealand)
On Mon, May 28, 2012 at 3:23 PM, Mike van Bokhoven <mike at fenz.net> wrote:
On 28/05/2012 12:11 p.m., Chuck Guzis wrote:
A sure sign is a "squealing" or other
noise when the drive is reading a
disk.
Interesting - now I'm mentally comparing the disk to a violin string, and
the head to the bow/hair, though the roles are all swapped around;
grippiness perhaps provided more by the disk than the head, for instance.
I'm imagining the slightly sticky failing oxide causes the gripping like
rosin. Bit of a mad thought there...
Absent that, I go by brands; I don't trust Control Data or Wabash
floppies.
Strangely enough, the first disk I ever bought (I'd guess in 1980 or so)
was Control Data, and it spent years being squashed and bent in my school
bag, but it still works OK to this day. One sample doesn't mean much though!
The budget Dysans (pink label, not purple) were terrible also, but
fortunately you don't see many of those
survivng. Brown Disk, some Radio
Shack-branded disks (I suspect they were probably from CDC) and a few
others are equally bad. Read at your own risk.
A problem may be that we're in New Zealand - there is some commonality in
brands, but a lot of difference too. For instance, we'd see Dick Smith
disks in place of Radio Shack. Plenty of Dysans here though.
You can test a 5.25" disk for flaking by scratching the oxide near the
hub with an X-acto knife. Go easy--you can make
any media flake, but the
bad stuff *really* flakes. It doesn't harm the data, since you're
completely outside of the storage area.
Good idea, I'll mention that to my friend and see if he's willing to give
it a go.
Beyond that, look to how the disks were stored. If they were stored at
40C or above, expect trouble from any disk. While
most people use
isoproanol to clean heads, I've found some sticky oxide that won't come off
using alcohol. For that, I CAREFULLY use a swab moistened in
perchloroethylene, being careful to steer clear of any plastic surfaces.
Fortunately, in NZ we'd pretty much never see 40 degrees C, though in roof
spaces etc I'm sure it can reach and exceed that. I'll ask. In the end,
maybe figuring out an easy way to clean the heads is best. I've considered
making an easy-access drive, where the electronics and case can be moved
without needing to loosen any fasteners, meaning I can easily clean the
heads with a cotton bud or similar. When fiddling with 30 year old media,
regular failures are to be expected!
Mike