Filetypes

RISC OS uses a three-digit hexadecimal number to represent the type of a file. This information is stored with the file attributes and can easily be lost when transfering the to or from another platform. The Filebase maintains a comprehensive database of Filetypes, allowing you to lookup information either by hexadecimal code, or by type name (eg, FFF is the code for the 'Text' file type).

The latest version of The Unofficial Acorn Filetypes List (from which much of the information here is gathered) is available from http://foldoc.doc.ic.ac.uk/acorn/doc/filetypes.

Filetype (and module) registrations are now handled by RISCOS Ltd , allocate@riscos.com.

!Typeinfo

!Typeinfo by David Sharp intercepts attempts to run files of unknown type and tells you what programs can handle the type.

Downloadable Lists

The full list of filetypes stored on the Filebase is downloadable in the following formats:

• CSV - All entries | Registered Types Only | All Except Deprecated
• Text - All entries | Registered Types Only | All Except Deprecated
• HTML - All entries | Registered Types Only | All Except Deprecated

Overview

The minimum requirement for a valid allocation is that double-clicking the file loads an application and does something meaningful with it. Use existing file formats (not just within the Acorn world), and make data interchange as painless as possible. If your software is going to be distributed, get an allocated filetype to avoid clashes.

Types on the Filebase have one line for each different use of a filetype. Each line has the format:

• Type - Three hexadecimal digits
• Code - Status
  • R = This type is registered with the official list (maintained by RISCOS Ltd)
  • D = This type is deprecated - a registered or newer type exists
• Name - The short name for the type (File$Type_XXX)
• Description - The kind of data in files of this type
• Origin - The originator (author or company) of the filetype
• File Extensions/MIME types - Common filename extensions and MIME content-types used elsewhere