360K Floppies Used in 1.2 MB Drive May Be Unreadable (79538)
Double-sided, double-density 5.25-inch (360K) disks, when formatted in a 360K drive and then written to on a high density 5.25-inch (1.2 MB) drive, may no longer be readable in the 360K drive.
Conversely, disks formatted as 360K in a 1.2 MB drive and then written to in a 360K drive may no longer be readable in the 1.2 MB drive.
360K disk drives write a relatively wide track at 40 tracks per inch. 1.2 MB drives normally write at 80 tracks per inch, and therefore write a somewhat narrower data track. This renders the use of 360K disk interchangeably between the two drives as a less than reliable means of exchanging data, because the result can be a narrow data track superimposed upon a wide data track, or vice versa.
There are two methods to increase the reliability of disk data transfer between these two drive types:
To transfer data from a 1.2 MB drive to a 360K drive using a 360K disk, do the following:
• Start with a blank, unformatted 360K disk. In the 1.2 MB drive, format the disk using the /4 or /f:360 option, as follows:
format x: /4
or, for MS-DOS version 4.0 or later,
format x: /f:360
(where "x" is the 1.2 MB drive designator, and assuming the MS-DOS directory is in the path).
This will allow the format of the 360K media in the 1.2 MB drive.
• Perform reads and writes on the media while in the 1.2 MB drive, but perform ONLY reads from the disk while in the 360K drive. Writing to the media in the 360K drive may render it unreadable.
To transfer data from a 360K drive to a 1.2 MB drive using 360K media, do the following:
• Start with a blank, unformatted 360K disk. Format the disk as normal in the 360K drive.
• Perform reads and writes on the disk while in the 360K drive, but perform ONLY reads from the media while in the 1.2 MB drive. Writing to the media in the 1.2 MB drive may render it unreadable.
For more information on the FORMAT command, consult your MS-DOS manual.