Diskcomp--Notes

Invalid drive for diskcomp

The diskcomp command works only with floppy disks. You cannot use diskcomp with a hard disk. If you specify a hard disk drive for drive1 or drive2, diskcomp displays the following error message:

Invalid drive specification
Specified drive does not exist
or is non-removable

Diskcomp messages

If all tracks on the two disks being compared are the same, diskcomp displays the following message:

Compare OK

If the tracks are not the same, diskcomp displays a message similar to the following:

Compare error on
side 1, track 2

When diskcomp completes the comparison, it displays the following message:

Compare another diskette (Y/N)?

If you press Y, diskcomp prompts you to insert disks for the next comparison. If you press N, diskcomp stops the comparison.

When diskcomp makes the comparison, it ignores a disk's volume number.

Omitting drive parameters

If you omit the drive2 parameter, diskcomp uses the current drive for drive2. If you omit both drive parameters, diskcomp uses the current drive for both. If the current drive is the same as drive1, diskcomp prompts you to swap disks as necessary.

Using one drive for the comparison

If you specify the same floppy disk drive for drive1 and drive2, diskcomp does a comparison by using one drive and prompts you to insert the disks as necessary. You might have to swap the disks more than once, depending on the capacity of the disks and the amount of available memory.

Comparing different types of disks

Diskcomp cannot compare a single-sided disk with a double-sided disk, nor a high-density disk with a double-density disk. If the disk in drive1 is not of the same type as the disk in drive2, diskcomp displays the following message:

Drive types or diskette types not compatible

Using diskcomp with networks and redirected drives

Diskcomp does not work on a network drive or on a drive created by the subst command. If you attempt to use diskcomp with a drive of any of these types, diskcomp displays an error message.

Comparing an original disk with a copy

When you use diskcomp with a disk that you made with the copy command, diskcomp may display a message similar to the following:

Compare error on
side 0, track 0

This type of error can occur even if the files on the disks are identical. Although the copy command duplicates information, it doesn't necessarily place it in the same location on the destination disk. For more information about comparing individual files on two disks, see the fc command.

Diskcomp exit codes

The following list shows each exit code and a brief description of its meaning:

0 The disks are the same.

1 Differences were found.

3 A hard error occurred.

4 An initialization error occurred.

You can use the errorlevel parameter on the if command line in a batch program to process exit codes returned by diskcomp.

More Information About Diskcomp

Diskcomp--Examples

Diskcomp