Basically finished

I added a bunch of the orignal error messages from a 1964 manual, and now it is feature complete (minus DIM and DEF)

What i’d like to do next is create the terminal interface as described in this manual, on pages 16-18.
It would be cool to say HELLO and then type in a user id, program id, write the program and save it, and even run it. I think it would feel very fitting!