Msg: 3638 *Conference*
12-24-92 17:18:51
From: FRANK PERRICONE
To : RICHARD HANSON
Subj: HD DISKS
In order for a HD disk to hold so much more info without each bit of info exerting a magnetic force that could scramble the bits next to it, they have to make them a lot more resistant to magnetic forces, which means the read/write heads have to be able to put a lor more magnetic energy into it. This is measured in something called oersteds (I could be mispelling it). Formatting an HD 3.5" disk as lower density sometimes works, but even when it does, the signals tend to degrade over time because they weren't pushed hard enough into the medium, so to speak, so they're not reliable. The old 5.25" disks we all used to use long ago didn't hve this problem because they made them high-density in a different way, althogh the disk manufacturers wanted us to believe they did so we'd buy more expensive disks than were necessary (remember the old disk-notching days?), but with 3.5" disks, it really is necessary.