Peter, what version do you have, v1 files have to be opened and saved in v2 format first, then they should open, or there is also free v4 which will open v2 files, and once saved should open in most modern TC's (as a test I could open v2 and v4 files in TC 2017).
For TC V2 see Here
(needed to convert your v1 files)
and TC v4 is Here
(Its called TC learning edition)
Both are free to download and use ##Edit## assuming you have a PC capable of installing them, I have them on a windows xp computer, and in the first thread above the person was using v1 on windows 7 with virtual xp ##End Edit##