"Laddie however will transparently convert files like this on the fly, which is convenient when you know about it, but creates confusion exactly like you experienced when you don't know about it."
As I've said Laddie is more of a file transfer service/tool than an attempt at a high fidelity "TPDD emulator" In this case, confusion was going to happen either way, it would just be different confusion and originates from an incorrect extension. Just the confusion would be "I inloaded this program with TEENY and LaddieAlpha and now my Model 100 is doing lots of weird stuff and I lost all my files" instead of "why is this extension different than the file on the host?" or the best kind of confusion, "why did this Just Work (TM), make it stop?!" I will say this was a situation I hadn't thought of, a new confusion variant. When you're using TEENY you aren't presented with a directory, so you don't see LaddieAlpha presenting the corrected extension given the file content. It's like the file you know is there, isn't accessible. It really is, just under the corrected extension. So my fix helps a TEENY user only in that it doesn't let them corrupt their filesystem. Since there's no way they would know the extension is different (or they would have renamed it themselves). The only thing to better support TEENY safely would be to instead either "Just Fail (TM)" by appropriating some TPDD error or else tokenize the file on the fly. I considered tokenization before and resisted the temptation. Putting a correct extension is one thing. It's a simple algorithm I can do reliably. Tokenization on the other hand is very Model T variant specific and although if I know the variant I can do a good job of tokenizing, I'm not sure it would be high fidelity to what the variant would do. -- John.