I think that it's not really a TXT file. I think he had to name it TXT to get the BBS to swallow it, or the BBS automatically added ".txt" to a file without an extension. It's probably a linux binary.

Many browsers will interpret a text file oddly at download time, inserting carriage returns in bad places if the file is a binary file. So I'm not sure if it'll run properly from the posted file, I haven't tried it.

Best to zip or tar any binary files before posting them on the web.