What is MIME type "image/x-atari-duo"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The MIME type image/x-atari-duo designates disk image files for Atari systems. It preserves the full content and structure of original Atari disks. Files using this type include those with extensions such as DU1, DU2, and DUO.

The format captures low-level details like tracks and sectors. This accuracy is key for running software exactly as it did on vintage hardware.

Main use case: Emulating Atari disks on modern PCs.
Additional use case: Archiving and backing up classic Atari software.
Key fact: The image keeps the disk’s original structure intact, ensuring compatibility with specialized applications.

The image/x-atari-duo type is mainly used by retro computing enthusiasts and emulator developers. For further details on Atari file formats, visit filext.com.

Associated file extensions

.du1, .du2, .duo

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: image/x-atari-duo

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="image/x-atari-duo">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'image/x-atari-duo');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.du1, .du2, .duo

FAQs

What is the image/x-atari-duo MIME type used for?

This MIME type represents disk image files for vintage Atari computer systems. It specifically identifies files with extensions like .duo, .du1, and .du2, which contain the exact structure of original Atari floppy disks for archiving and emulation purposes.

How do I open a file sent as image/x-atari-duo?

You cannot open these files with a standard image viewer; you need an Atari emulator such as Steem, Hatari, or Saint. These applications simulate the Atari hardware and allow you to mount the file as a virtual floppy disk to run the software contained within.

Why does my browser download the file instead of displaying it?

Browsers like Chrome and Firefox only display standard web images (like JPEG or PNG) and do not support proprietary disk image formats. When a server sends the image/x-atari-duo header, the browser treats it as an unknown binary file and forces a download so you can use it with a local emulator.

How do I configure an Apache server to serve these files?

To ensure browsers and download managers handle the files correctly, add the type to your .htaccess or configuration file. Use the directive: AddType image/x-atari-duo .duo .du1 .du2. This tells the server to associate those extensions with the correct MIME type.

What do the extensions .du1 and .du2 signify?

These extensions usually indicate a spanned or split disk image set. For example, a large program that originally spanned multiple floppy disks might be archived as game.du1 and game.du2. You may need to combine them or load them sequentially in your emulator.

Is image/x-atari-duo a standard IANA type?

No, the x- prefix indicates that it is a non-standard or experimental subtype. It is not officially registered with the IANA but is used by the retro-computing community to specifically identify Atari DUO format disk images.

Can I convert DUO files to other Atari formats?

Yes, specialized tools like MSA Converter can often convert image/x-atari-duo files into more common raw formats like .st or Magic Shadow Archiver (.msa) files. Conversion is useful if your specific emulator does not support the DUO format natively.

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 are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.