9 Feb
2009
9 Feb
'09
1:28 p.m.
That's part of my questions too,
as time goes on, these disks we have *will* eventually fail. the magnetic flux will waver,
and data will be lost,
they'll no longer be useful for alignment. and the longer time passes, the worse it
gets, same too with the drives.
that's part of what I was saying, for current conditions, "good enough"
might be all we have, it's better than nothing.
and as time goes on, we may be stuck with it.
I'm curious if anyone out there would spend the time/money/effort to recreate these
things properly, over time.
and then, what do you do in one generation? or two? one is bad enough, none of us are
getting any younger.
I'm reminded of that question someone posted, about putting a computer and software in
a time capsule, to be reopened in 50 years.
turned out to be totally impractical (as the components wouldn't last).
do we just preserve the software in some sort of digital format, and 'hope' that
someone carries it on?
at least in digital form, we can transfer it from media to media every few years and hope
to keep it viable.
that's one reason I'm digitizing all the software I have, I have rare stuff that
will cease to exist if I don't.
Dan.
Date: Mon, 9 Feb 2009 13:13:51 -0800
From: ian_primus at yahoo.com
To: cctalk at classiccmp.org
Subject: Alignment disks, and the creation thereof
I've been reading the now increasingly mistitled thread on alignment disks, and
it's gotten me thinking. What IS required to make alignment disks? I've always
aligned malfunctioning floppy drives "the wrong way", using a known good disk -
or an original software disk. On the Commodore 64 (and most systems, really), you can get
the drives working well enough like this, but as others have pointed out, it's not the
"right way". I just don't have any alignment disks. "Good enough"
is much better than "not at all", and I don't mess with the drive alignment
unless I have to. I'd love to be able to align drives properly though. And that
requires an alignment disk.
There are different kinds of alignment disks too - analog and digital, ones that are
intended to be used with a special program on a particular computer, and those intended to
be used with a scope.
With today's modern machining technology, it should definitely be possible to create
a system to write new alignment disks. Starting with a standard floppy drive, you could
replace the stepper drive with something more precise and controllable. Then, you have to
somehow accurately calibrate this whole thing. Is there a document out there that
describes the track layout of a standard (say, 5 1/4" 48tpi, 40 track) diskette?
There has to be a spec, one that describes exactly the distance between tracks, the width
of a track, and the distance from the center hub to the beginning of the first track. If
you had that information, and precision measurement tools, one could set up and calibrate
the drive to spec.
Then, of course, there needs to be a controller for the thing, a computer interface to
control the precise positioning of the head, as well as being able to read/write to the
disk.
It's possible. It's beyond the equipment and tools at my disposal, but it's
definitely doable for a hobbyist who has access to a machine shop and good tools.
Anyone out there a machinist? :)
-Ian
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