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Re: After 20 Years, I'm This Close To Finally Escaping Data Rot -Thoughts?



winston19842005 wrote:
On 2/25/10 9:00 PM, in article C7AC9552.138FC%bjjlyates@NOSPAMbellsouth.net,
"winston19842005" <bjjlyates@NOSPAMbellsouth.net> wrote:


On 2/25/10 8:40 PM, in article
YqOdnR78WfkZuxrWnZ2dnUVZ_r0AAAAA@giganews.com, "Michael J. Mahon"
<mjmahon@aol.com> wrote:


winston19842005@yahoo.com wrote:


On other computer brands, we had to make both a notch and an index
hole through the jacket for the 2nd side of a flippy, so we don't have
the issue.
I suppose doing so "after the fact" might work? As long as you are
precise.

Just out of curiosity, what is the technique for making a second
index hole in the jacket without damaging the media?

First measure where the hole is on the other side, and make a mark on the
jacket as a template. If you are doing a lot of disks, I'd suggest making a
separate template altogether. I used a pencil to lightly fill in the hole
where I needed to punch.

Then, using an old-fashioned hole punch, you carefully lift the jacket away
from the media, slide it underneath lining it up with the mark and punch.
Repeat for the other side.
>>
Did it with dozens of disks. There was a time when I had a bad disk drive
and it didn't appear to be working. I actually used a pair of scissors to
cut away a good portion of the jacket exposing the index hole. Once I
replaced the drive, the disk worked perfectly.

So any possible creasing or magnetic disturbance of the media doesn't
matter because the index hole is a fraction of an inch ainside the
innermost track...  I suppose that would work.

Still, modifying the drive to add another sensor seems the best way
to enable "flipping" if lots of disks are involved.

But thinking about it, this probably wouldn't work after-the-fact for a disk
that was written using an index hole on the other side in relation to the
read/write area. We had to punch this hole prior to using the 2nd side, so
the data was written in relation to the new hole - both sides of the flippy
having the same relation between the index hole and read/write area.

That shouldn't be an issue, since the only purpose of the hole in the
jacket is to expose the pre-punched index hole in the rotating media
to the index hole sensor in the drive.

But I do remember a friend removing the media completely and flipping it
over inside the jacket to read a disk on an Apple II that we had in school -
for some reason it wouldn't read the other way.

It should have worked--something else was wrong.

-michael

NadaNet and AppleCrate II: parallel computing for Apple II computers!
Home page: http://home.comcast.net/~mjmahon

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