To learn more about the mystery first character, the search term is “Fortran carriage control”. I’m not sure all the choices were ever standardized, but you can typically use + (don’t advance the carriage; i.e., overprint the last line), 0 (double space), or 1 (“form feed” to the next page).

I can remember my Fortran teacher illustrating these with little hand gestures as if he was holding the knob on a typewriter carriage.

I also remember someone at college who had a grudge against the computer minions behind the glass who took your printout and filed it in a cubbyhole for you to pick up. He would run a job to repeatedly print

+________ (…132 total underscores)

which had the effect of cutting the paper, which would drop out of the bottom of the printer so the minions had to open up the printer and refeed the paper.