Trying to open illustrator 3.0 files saved as .txt
I have dozens of Illustrator files I made in 1990 with version 3.0. These were originally made on a Mac, but then went through many years of storage in systems that were PC. Now I work on Macs again.
When I pull up the old directories, I now see all the 3.0 files listed as .txt (interestingly, I have a few files also made in 1990 on Ilustrator 1.8, and these still have .ai tags)
The files with .txt do not open. I have tried changing the file extension to .ai or .eps, but that does not work. When I look at the files with a text editor, I see all the typical stuff, but I am not expert enough to recognize what might be missing.
Any suggestions?

