For example, even in the tiny copy program example, from the introductory chapter, once you include the primitive getc and putc subroutines, there are 7 symbolic constants: MAXLINE, MAXCARD, NEWLINE, STDIN, STDOUT, EOF, SPACE and character, which is really an integer and gets replaced with integer by some mythical preprocessor (chapter 8). Anyhow, in the modern world, MAXLINE and MAXCARD don't really have meaning, but they can magically be treated as lines of a file, the rest do have meaning, but they don't evaluate to the same things in Fortran-land as in modern-land. STDIN is 5 and STDOUT is 6 (card reader and punch LUNs, again some magic that lets them be treated as terminal input and output),  EOF is -1, SPACE is 32, NEWLINE is 10.

Pretty sure that EOF is _still_ -1.  SPACE and NEWLINE also look pretty familiar and their values haven't changed, although we might spell them a little differently these days.