4 Oct
2011
4 Oct
'11
12:45 p.m.
I did enough experiments to see that I had no
problems reading floppies
other than those that were recoreded near the monitor.
OK. I ssume areas of the disk that were not written near the monitor were
unaffected.
My guess is that it upset the bias so that it shifted
the depth over time=
There's nop bias (in the normal magnetic-recording sense of an HF
oscillation) in disk deives (and they use DC to drive the tunnel erase
head too). I wonder if somehow, in the presense of the normal write
field, the alternating field from the monitor was recorfed, causing extra
transition...
I don;t suppose you still have such a disk? If so, it would be
interesting to see what a efective track contains, both at the output of
a normal floppy drive trying to read it, and as an analgoue signal at the
putput of the read amplifier.
-tony