Bring me the head of a Pi Zero

I am here to beg for mercy for all Pis. All this head removing has to stop, well not really, off with the head, but I want the head not the rest.
Can I a get a tutorial on the other end of things simple quick up to a console / terminal for warm human loving interactions. I am particularly interested in a RS232 serial console and simultaneous connect via USB to PC (so I can Xmodem over the latest episode of Zork) with the option to have real handshaking so I don’t lose a single time travelled, Z80 generated bit. I have built a Zeta 2 with a 20MHz Z80 (yep sheza rocket alright) I have been using one of Geoff Graham’s ASCII Video Terminals that I built. It works okay but it just does not render fast enough when running at full throttle. And the lack of good handshaking (mostly my fault for not using a module with handshaking), well it looks like the output of a migraine afflicted Digital Research code monkey.

-Your friend Mark the merciless.