What is MIME type "image/x-commodore-vbm"?

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

image/x-commodore-vbm is a MIME type for a specific bitmap image format. It represents the VDC BitMap version 3 used on Commodore systems.
It stores raw graphic data in a way that fits the hardware design of vintage Commodore computers.

Used in retro computing and emulation projects.
Preserves original graphics for vintage software archives.
Helps software identify and correctly process Commodore bitmap images.

Files with this MIME type are commonly found as BM or VBM files.
They contain image data optimized for Commodore video display hardware.

For more details on MIME types and related file formats, please check the IANA Media Types resource.

Associated file extensions

.bm, .vbm

Usage Examples

HTTP Header

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


    Content-Type: image/x-commodore-vbm

HTML

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


    <a href="file.dat" type="image/x-commodore-vbm">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-commodore-vbm');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.bm, .vbm

FAQs

Can modern web browsers display image/x-commodore-vbm files?

No, standard browsers like Chrome, Firefox, and Edge do not natively support the Commodore VDC BitMap format. If a user tries to open a file with this MIME type, the browser will typically prompt to download the file instead of displaying it.

How do I open a .vbm or .bm file?

To view these files, you usually need specialized retro-computing software, an emulator (like VICE), or an image viewer that supports legacy formats, such as XnView or IrfanView. These tools can interpret the raw graphic data intended for Commodore hardware.

How do I configure Apache to serve .vbm files correctly?

You can enable support by adding the MIME type definition to your .htaccess file or main configuration. Add the line: AddType image/x-commodore-vbm .vbm .bm to ensure the server sends the correct headers.

What is the correct Nginx configuration for this MIME type?

For Nginx, open your mime.types file (usually located in /etc/nginx/) and add the entry: image/x-commodore-vbm vbm bm;. Reload Nginx to apply the changes.

Why does the MIME type start with 'x-'?

The x- prefix in image/x-commodore-vbm signifies that it is a non-standard or experimental type not officially registered with the IANA. It is a convention used to identify proprietary formats specific to Commodore systems.

How can I convert a Commodore VBM file to a PNG?

You can use conversion utilities found in Commodore emulation toolkits or multi-format image viewers like RECOIL (Retro Computer Image Library). Once opened, you can export the .vbm file to a modern web-friendly format like PNG or JPEG.

Are .bm and .vbm files the same thing?

Yes, both extensions refer to the same VDC BitMap format. While .vbm is the descriptive extension, .bm was frequently used on systems with stricter filename length limitations.

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.