In order to use a PDP-8 you don't need anything
but the computer that
is "zero overhead."
Sure, if you want to toggle code in on the front panel.
You can do that on your uVAX as well. But the front panel is a dumb
terminal.
Thus for equivalent functionality, you only need one item more than you
would on a PDP-8. (OK, two items if you count the serial cable.)
You'll probably say that you don't want to type in all of the VMS object
code by hand, but I'd venture that you don't really want to toggle in
OS/8 either.
Eric