When your data files have such an exotic format that even Spectrum Viewer cannot read them anymore, you can write a plug-in converter program which SV can call to convert the file to a format it can read. This program should be an exe file which takes two arguments: the input file (the file to convert) and the temporary output file. Both arguments will be generated on-the-fly by SV when it calls the plug-in program.

When opening a file with a plug-in, the following happens. You open the files in SV just like you used to, with the "open file" dialog box. SV will now go down the file list you have created (all the selected files), and will call the plug-in program for each file of the list. The plug-in program will generate a converted temp file, SV will read the converted temp file, and delete the converted temp file after reading. That way it will be like the conversion never took place and SV did read your original data file from its original location.

I've written an example program which you can use as a skeleton for writing your own converter programs. The compiled version of this program is called PluginFileConverter.exe, and it is present in the SV program folder. You can test the use of this plug-in converter program with the "Plug-in" preset on the "Open special format" panel.