Creating a Superfloppy Disk Image
ImDisk is required - download and install. Basic usage is covered below (see here for a full range of options).
We will be using the formular covered here, To create a 1 GB (1024 MB) disk image -
- 1024 divided by 7.84423828125 = 130.5416744475568
- Cylinders = 130.5416744475568 rounded up/down to the nearest whole number = 131
- Total Sectors = 131 multiplied by 16065 = 2104515
To create a disk image using ImDisk open a command prompt (Start > Programs > Accessories > Command Prompt) and -
- Either use the following command to create and mount the image, then format it manually (e.g. right-click in explorer and select Format...) -
- Use the following syntax to create the disk image (where Total_Sectorsb parameter is value calculated in step 3 appended with the letter b for blocks, DRIVE is the mount point (the drive letter to be allocated to the mounted disk image) and File is disk image to be created -
imdisk -a -s Total_Sectorsb -m DRIVE: -f File [enter]
Using the figures calculated in the 1.5 GB example, use the following command to create disk image C:\my_disk.ima as drive R: -
imdisk -a -s 2104515b -m R: -f C:\my_disk.ima [enter]
- or use the following command to create, mount and format a disk image -
- Use the following syntax to create the disk image (where Total_Sectorsb parameter is value calculated in step 3 appended with the letter b for blocks, DRIVE is the mount point (the drive letter to be allocated to the mounted disk image), File is disk image to be created and Filesystem /Options is the filesystem to use in formatting the disk image with additional command line parameters -
imdisk -a -s Total_Sectorsb -m DRIVE: -f File -p "/FS:Filesystem /Options" [enter]
Using the figures calculated in the 1.5 GB example, use the following command to create disk image C:\my_disk.ima as drive R: and format it using NTFS compression -
imdisk -a -s 2104515b -m R: -f C:\my_disk.ima -p "/FS:NTFS /C /Y" [enter]
- Unmount the disk image using the following command syntax (where DRIVE is the drive letter allocated to the mounted disk image - replace -d parameter with -D to force dismount) -
imdisk.exe -d -m DRIVE: [enter] -
imdisk.exe -d -m r: [enter] -
The above steps can be automated using the following batch file (highlight the text below and hold [ctrl]+[c] to copy and [ctrl]+[v] to paste into notepad, then save with a .cmd file extention) -
If using the above batch file, edit the following settings -
- set size= - use value calculated in step 4 (Total Bytes)
- set disk= - disk image (including path) to be created
- set mount= - drive letter to allocate to mounted disk image
Note - a disk image created with this method and formatted with NTFS has been known to display errors when mapped to memory (see boot-land topic here). The 1 GB disk image created in the example above produced the following error -
NTFS BPB found with 0xEB (jmp) leading the boot sector.
info: BPB total_sectors(2104514) is less than the number of sectors in the whol
e disk image(2104515).
probed C/H/S = 131/255/63, probed total sectors = 2104514
The above error did not effect the operating system, which booted successfully and ran without errors. Interestingly the same image did not display any errors when formated using FAT or FAT32.