I've just got one of these, the interface seems to work but I can't work how you use it.

I guess you have to open, save then close, not sure of the syntax to use. Can anyone help. For instance if I have a program called Hangman which is stored on my c:/ drive, how do I transfer the contents onto the '74? The manual talks about file numbers, do I just put 1?!

Really struggling, so any help would be appreciated.