Which MIME types are related to file extension ".cqm"?
The .cqm file extension is associated with 1 MIME types:
A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.
About .cqm Files
CQM files are disk images created by the CopyQM tool.
They store a complete snapshot of a disk or partition in binary form. The MIME type application/octet-stream indicates a generic binary file with no inherent text data.
- Backup: They capture an exact copy of disk data for recovery purposes.
- Replication: They aid in duplicating disk content to another drive.
- Archiving: They preserve a disk’s state for long-term storage.
As stated by FilExt.com, this format is specially tailored for disk imaging and backup routines.
Relationship between file extension and MIME type
A file extension is a suffix at the end of a filename that indicates what type of file it is. File extensions help both users and operating systems identify what application should be used to open the file.
File extensions are typically separated from the filename by a period (dot) and consist of 2-4 characters, though they can be longer. For example, in the filename "document.pdf", ".pdf" is the file extension.
File extensions are closely related to MIME types, as they both serve to identify the format of a file. However, while MIME types are used primarily by web browsers and servers, file extensions are used by operating systems and applications.
Associated MIME types
FAQs
What is a CQM file?
A .cqm file is a disk image created by the CopyQM utility, developed by Sydex. It stores a compressed, binary snapshot of a floppy disk or hard drive partition, primarily used for backing up data or duplicating disks in older computing environments.
How do I open a CQM file on Windows 10 or 11?
You cannot open a .cqm file directly with modern Windows applications. You must use the original CopyQM software to restore the image to a physical disk. Since CopyQM is a legacy DOS program, you will likely need to run it using an emulator like DOSBox.
Can I convert a CQM file to ISO or IMG format?
Direct conversion is difficult because the .cqm format uses proprietary compression. The most reliable method is to use CopyQM to write the image back to a physical disk (such as a floppy via a USB floppy drive), and then use a modern tool like WinImage or ImgBurn to create a new .iso or .img file from that disk.
Why can't I view the files inside a CQM archive?
A .cqm file is not a standard file archive like .zip or .rar; it is a sector-based disk image. The operating system sees it as a generic binary stream (often identified as application/octet-stream) rather than a folder structure, so you must restore the image to a disk to access individual files.
Is the CopyQM software still available?
CopyQM is considered abandonware and is no longer officially supported or sold by Sydex. However, it can often be found on software preservation websites or vintage computing archives for users who need to recover data from old .cqm backups.
What is the correct MIME type for serving CQM files?
There is no specific IANA-registered MIME type for CopyQM images. When hosted on a server, they are typically served as application/octet-stream, which instructs the browser to treat the file as generic binary data and trigger a download.
General FAQ
What is a MIME type?
A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.
MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.
MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.
How do I find the MIME type for a file?
You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.
Why can one extension have multiple MIME types?
Different programs and historical usage may assign various MIME identifiers to the same file format. Listing them together helps maintain compatibility across tools.