Setup a x3270 Terminal emulator

Install the software

sudo apt install x3270

This will also install some fonts but if you use a different profile, more will need to be installed:

Install and setup the fonts

sudo apt install xfonts-100dpi xfonts-75dpi

Then add the new fonts to xset:

xset fp+ /usr/share/fonts/X11/100dpi/:unscaled
xset fp+ /usr/share/fonts/X11/75dpi/:unscaled
xset fp+ /usr/share/fonts/X11/100dpi
xset fp+ /usr/share/fonts/X11/75dpi

Update the font cache so the x3270 profile font is recognized.

xset fp rehash

Setup the x3270 profile

Search the internet for examples of x3270 profiles.

This is the x3270 profile I use.