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ziloo
February 16th, 2006, 10:25 AM
Dear Hardware fans,

Just today, I formatted a DS/DD floppy (5.25 ", 48 tpi) on a Teac FD55 drive. Not knowing that it was not a HD floppy :oops: , I formatted it for 1.2 Meg. After formatting was completed, it reported 930 kb useable space, and 320 kb (approximate numbers) of bad sector :evil: . Once I found out that the floppy was for 360 kb capacity (am I correct or it is 720 kb), I reformatted it for 360 kb and then everything was fine and no bad sector was reported :lol: .

1- Hadn't I realized that it was a 360 kb floppy, could I have gone on
my merry way and saved 930 kb data on a 360 kb floppy?

2- Where did the bad sector reading come from?

mbbrutman
February 16th, 2006, 11:01 AM
I would read this:

http://mail.magnaspeed.net/~mbbrutman/PCjr/diskette_handling.html

To make a long story short, there is a difference between double density (360KB) and high density (1.2 or 1.44MB) media. A different amount of magnetic 'force' is needed to write to the two different types of media.

Formatting a high density disk in a double density drive (or vice versa) may work for a little bit, but expect to lose data. Which is what you experienced - it formatted, but it didn't work very well. If you had proceeded to write data onto it, there would be no expectation that the data would be readable in a few hours or days.