If in True Dos Mode you should be able to press the 'Print Screen' key
(unless you have a USB printer which may or may not work in DOS mode.)
If in a DOS window, press "Print Screen", open paint and "Paste" invert the
colors and trim, print to printer.
If you are trying to print the output from a DOS command append >LPT1
to the end of the command.
DAOQ.