On 04/01/2019 21:32, afachat@gmx.de wrote: > Only if you factor in the length of an encoded byte, you get something like > "bit per inch" values. But they have nothing to do with the media quality, > only with the encoding method. Some people claim the labels just described how they were formatted, as if people didn't know how to format them when they opened the box. With the plethora of different systems available that would have required formatting anyway, then it seems a largely pointless exercise if it's true. I worked somewhere that used Pet's, I might have some of the disks that were "thrown out". I thought I'd seen some quad density disks at some point. > The standard FDD controllers did not have zone bit recording indeed. That they > did not introduce it when going to 80 tracks or even HD is a pity. I guess the > problem was that DOS was unable to cope with different numbers of sectors on > different tracks, so it would have been wasted anyway. The Sirrius/Victor 9000 had zone recording and ran DOS. A variable speed floppy disk like the Mac or a variable speed floppy controller would have cost more money, neither part was designed specifically for or by IBM. It's interesting that it took until 1993 before Microsoft distributed floppy disks with a larger sector size and smaller sector gap.Received on 2019-01-05 04:00:03
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