That makes me chuckle. dhex first starts up asking you to press certain keys so that it can learn how your terminal works. It allows you to press ESC if you don't want to do that. But ESC does not work because it has not configured your keys.... I tried it on a Pi and my PC, the only key that works...

So which would you exect to work?
dhex myfile.mid - where the two files are in very different locations

or does it need the full path name: dhex /home/pi/mytests/myfile.mid

Would that be the correct path name? (up to the /home/)

Hopefully my comments aren't too stoopid. I'm new to the Pi but not to computers. As a pi-noob there seems to be a few options for the display, HDMI, plug-on small LCD display and the A/V connector. What's a little confusing is what data they send out as in, are they just different ways of displayin...

I'm similar. I have a Pi B3+ and bought a Waveshare 3.5" RPi LCD and was planning on using it as a data display screen but still keep the HDMI large screen for other uses. Reading the Waveshare wiki it seems I can only toggle between the two, one or the other not have both running at the same time, ...