Quote:
Originally Posted by mcbpete
I'm assuming the hole would be have to be bloody tiny due to the density of the data on the disk, a hole visible to the eye would've corrupted too much of the disk I would've thought.
|
I tried to think on the question of the size of the hole.
We can calculate what is the maximum that would create problems
The disc has a circumference (on the outside) of about 3,5*2,54*PI = 27,93cm
The rotation speed is 300RPM with 2us MFM cells, so 100000 cells (on Amiga usually a little more).
It is not difficult to have a gap of 5000 MFM cells for amiga disks considering that it writes all the sectors side by side.
This give us 27,93/100000*5000=1,396cm.
Ok ok, on disk inner tracks the circumference is lower and therefore the hole a little smaller.
And again, this measures an arc and not a straight line..
But yes, the hole can be very big
Anyway the problem at that point is not in the hole per se but the completely unbalanced and bent surface that would not allow a reading without errors.
In any case a visible hole is absolutely possible and tolerated (
if the writing is done specifically, a hole by damage in random position is highly likely to create illegible data).
But for what? There is better method to make the same results (weak bits).