Both .tvc and .fm1 files were known to be used in old Lotus 1-2-3 and only this ancient program is most likely capable of direct conversion or transformation of data between those two files. We sadly do not know about any other software that could handle or convert these two old file types.
Convert IBM Lotus 1-2-3 table file to Lotus 1-2-3 release 2.x spreadsheet file.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert tvc to fm1 on Windows
Old spreadsheet program from IBM
Convert from tvc file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.