The 8-Bit Era's Weird Uncle: The TI-99/4A

I had one for a while in my early teens and it had the floppy disk drive option. I did some sprite and graphics programming. It's obviously been a long time and I was young so I could be mistaken, but one bad experience I had with it was that the filesystem considered a file either a program or data and there was no obvious way (to me) to switch between the two. Well one day the machine decided that my basic files were data and not programs and so I lost them.

After so long I have no idea, but... that floppy file system also had a notion of copy-protected files. It turned out to be straightforward to work around that copy protection, so maybe there was some similar way around the data/program thing.

(All I remember is reading the docs of the filesystem calls and thinking "hm, could you do thus-and-so" and being a bit surprised it just worked.)