About DMF

DMF and 1.68 MB format are the same physical format. (80 tracks, 21 sectors/track). The 1.68 MB format has 224 entries in the root directory, and a cluster size is 512 bytes. The DMF format has 16 entries in the root directory, and the cluster size is 1024 or 2048 bytes. Microsoft uses DMF 2048 for the floppy version of some of their new software. Windows 95 and Windows NT 3.5x read and write directly in DMF format, and you will need FDREAD to read these files under MSDOS or Windows 3.1.

Some Microsoft DMF floppy disks contain information to make them write-protected under Windows 95 or Windows NT 3.5x. To write to these floppy disks, you will need to reformat them.

The DMF format is often used for distribution floppies under Windows 95 and Windows NT.

Under Windows 95, unlike other operating systems, formatting for DMF uses the BIOS. You can have compatibility problem on some computers. If you experience such problems, I suggest you try the following:

- If your system has a flash BIOS, upgrade the BIOS to the latest release. If you have an Intel motherboard, you can find BIOS upgrades at ftp://ftp.intel.com/pub/bios.

- Format the floppy to 1.44 MB before trying DMF.

- Try to get more conventional memory (ideally by having a near empty config.sys) .

- Try using both winimage.exe and winima16.exe under Windows 95. (Ignore the message from winima16.exe that suggests not running using this O.S.) .

- download FDFormat (ftp://ftp.coast.net/SimTel/msdos/diskutil/fdform18.zip). Under DOS (or Windows 95 command line only without graphics interface - this is accomplished by pressing F8 and selecting 6 when booting) try 'FDFORMATAs is true with WinImage, FDFormat uses the BIOS. If FDFormat cannot format a disk at 1.68WinImage will also be unable to.

Some problems with DMF formatting under Gateway 2000 computers can be solved by downloading a BIOS update from the Intel FTP or web site (www.intel.com).

Under Windows 95, the following options are available In the Options Settings, Disk tab:

- If both Use new DMF format technology and Use new DMF technology for writing data also are checked, WinImage will use the new 3.0 DMF formatting code.

- If both Use new DMF format technology and Use new DMF technology for writing data also are unchecked, WinImage will use a slightly fixed version of the 2.5 DMF formatting code.

- If Use new DMF format technology is unchecked, WinImage uses the same code as version 2.20 to format (in fact, in WinImage 2.50, there was a bug, this checkbox didn’t do anything)

Some DMF related problems can be corrected by adjusting the disk gap. To change this setting, you must modify the registry. The key value to modify is HKEY_CURRENT_USER\Software\WinImage\iGapDmf. A value of "0" specifies the standard DMF GAP. One user needed "17" for a 2.88 driver. Please report any problems solved by modifying the GAP.