diskcopy

diskcopy was a command-line utility in MS-DOS and early versions of Microsoft Windows used to copy the entire contents of one floppy disk to another. Unlike simply copying files, diskcopy created an exact sector-by-sector replica of the source disk, including the boot sector, file allocation table (FAT), directory structure, and any hidden or system files. This meant that the target disk would be bootable if the original disk was bootable, and that fragmented files would also be copied in their fragmented state, preserving the original organization of the data.

The primary purpose of diskcopy was to create identical backups of floppy disks or to duplicate software distribution disks. The command typically prompted the user to insert the source disk and then the target disk into the specified floppy drive. If only one floppy drive was available, diskcopy would prompt the user to swap the disks multiple times during the copying process.

diskcopy was a low-level copy utility and could be used to copy disks of different formats (e.g., 360KB, 1.2MB, 720KB, 1.44MB), provided the floppy drive supported both formats. However, it was crucial that the target disk be of the same physical size as the source disk. diskcopy was unable to copy from, for example, a 5.25" floppy disk to a 3.5" floppy disk.

While useful for creating exact duplicates, diskcopy also had limitations. Because it copied sector by sector, it would also copy any errors or bad sectors present on the source disk to the target disk. This made it unsuitable for recovering data from damaged disks. Also, diskcopy was largely superseded by more versatile imaging tools with the decline in floppy disk usage. These newer tools can often handle different disk formats and storage media, and provide better error handling and compression options.