Converting Older Max Documents
Previous versions of Max had two different document formats: binary and text. This was originally a reflection of the need to save space; roughly, the binary format was the text format with a cheap form of data compression applied to it. In Max 5 there is a single, entirely new format based on the JSON specification. JSON is a way to specify data similar to XML, but far more readable since it resembles Javascript source code. In addition, Max 5 documents have entered the modern world: they are encoded with Unicode (UTF-8) and can be given long filenames.
While both the old and new documents specify a patcher in terms of objects and connections, the details of how this is accomplished in each format are very different. In addition, far more data at higher resolutions is saved in a Max 5 document, so Max 5 does not provide a way to "export" patches you create to the older format. Max 5 can, however, import patches, either text or binary, from older versions of Max. Below we describe some of the problems you may encounter when importing older documents.
Missing or Incompatible Objects
If you have an existing Max 4 folder and you just try to open one of your patches in Max 5, you may encounter a lot of missing files or objects, because you haven't set up your search path so that Max 5 can see the files needed by the patch. For more information on moving your Max 4 search path to Max 5, read Using Old and New Versions of Max on the Same Machine.
Some third-party objects that work in Max 4 will not work in Max 5. For the most part, you will see errors in the Max window saying the objects have failed to load, but in rare cases, incompatible objects may crash Max 5. Cycling '74 is working with developers of third-party objects to help implement any changes that need to be made.
Text Encoding
Max 4 documents use legacy Mac-specific text encodings (even on Windows) that needs to be converted to Unicode. In some cases when using non-Roman characters, conversion may not happen perfectly because the actual encoding in the document being imported cannot be identified.
Object Sizes and Fonts
Max 5 uses anti-aliased fonts that may be difficult to read when displayed at small sizes. The same patcher may be more readable in Max 4. You cannot switch off the anti-aliasing, but you have several options for making text larger:
Behavior of Specific Objects
Some Max objects no longer support certain messages or features. For a complete list, review Object-Specific Changes.