.$? File

The $? file extension is related to the TR-DOS ZX Spectrum file in HOBETA format.

TR-DOS is a disk operating system for ZX Spectrum with Beta disc and Beta 128 disc interface. TR-DOS and Beta disc were developed by Technology Research Ltd (UK), in 1985. Most disk releases for ZX Spectrum (especially modern programs) are made for TR-DOS.

This $? file type entry was marked as obsolete and no longer supported file format.

This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.

How to open:

Use compatible emulators to work with *.$? files.

How to convert:

As far as we know, this .$? file type can't be converted to any other file format. This is usually the case of system, configuration, temporary, or data files containing data exclusive to only one software and used for its own purposes. Also some proprietary or closed file formats cannot be converted to more common file types in order to protect the intellectual property of the developer, which is for example the case of some DRM-protected multimedia files.