Date : Tue, 13 Oct 2009 13:39:08 +0000 (GMT)
From : debounce@... (Greg Cook)
Subject: Re-using floppies
--- On Mon, 12/10/09, Mark Haysman <jumbos.bazzar@...> wrote:
> > me@...
> wrote:
> >
> >> Are 20-25 year-old 5.25" floppies safe to use
> regularly?
> >
> > I think it depends on the floppy, how it has been
> stored...
> >
> >
> >> My floppy drive still actually works and I don't
> want to risk damaging
> >> it.
> >
>
> Absolutely, although it does depend somewhat also on the
> type of drive
> you're using, and they type of head it has.
By far and away though, the most important factor is the brand.
Disregarding their relative quantities, about 60% of floppy disc
lines are still good, 20% are usable but mediocre, 20% are poor
and a couple are downright ugly.
> Most drives (of the 80 track variety) have square-looking
> heads for the top
> and bottom, with a ridge in the middle. These are very easy
> to clog with bad
> disks, and sometimes can be near impossible to clean fully,
> as the amount of
> scrubbing and force needed to get the clog out often
> dislodges the head or
> moves it on it's suspension, causing interchangability
> errors.
I can't say I've ever seen dirt in the groove but it's better not
to have one. The only brands that shed enough material to fill
it were Control Data (instantly) and one without a weld pattern
on the back (after a few minutes). The rest of the head is
polished smooth so deposits generally appear as small dark stains
at the points of contact. Easily removed by a few rubs with
isopropanol or failing that, acetone.
So in my experience a disc lets you know its character soon
enough (noise from the heads, seizing or dirt), and bad discs
cause a nuisance, but hardly damage. Do be careful with
gimbal-type copper mounts. The upper head on my drive hangs a
little wonkily after going through a whole box of cotton buds,
but still works OK.
> There are a few types of drive that have a round type head,
> that are
> perfectly smooth at the top - most 40 track drives have
> this type of head,
> and also some models of Teac 55 80 track single sided.
> There are some Canon
> and Teac drives that have this type for both the lower and
> upper head - that
> is the type you want to look for, as if you use a dodgy
> disk with them, the
> surface still gets coated, but as they're a smooth head,
> they're very easy
> to clean off. I use one of these drives for reading data
> off dodgy disks so
> I know I may destroy the disk, but not risk my drive.
I agree, round heads are preferable, given the choice. Who knows,
CDC and 'Spotless' may even be merely poor in those drives.
> For old 5.25" it is all about storage as Rick has said -
> rotate the disk by
> hand and see if you can see any mould markings on the
> surface. Also, the
> matt-look disks are more prone to the oxide coating coming
> off than the
> shiny ones, I recall that most 3M disks are the shiny type,
> so as long as
> they have no mould marks, then they should be good.
If it's only a few faint white rosettes then it's more like 'you
wouldn't want to use regularly' than 'it'll rip the heads off'.
The disc will read at least once with no problems but merits a
quick clean of the heads afterwards.
> Another quick test is noise. If you have a disk drive with
> a solenoid
> loading head (one that clicks when you read), put the disk
> in drive 0 and
> *CAT 1 (so the motor spins, but the head does not engage) -
> listen to the
> disk spining, if you hear loud regular noise from the
> drive, it's more than
> likely that the disk is knackered.
Wouter calls them "steam train disks":
http://wouter.bbcmicro.net/8bit/durability.html
One more thing, if a disc leaves a rim of brilliant white powder
on the heads then it should be cleaned off at once as it is
definitely abrasive on other discs.
Greg Cook
debounce@...
http://homepages.tesco.net/rainstorm/