Mike, as far as the RGB goes - without looking at and comparing the pinouts yet, do you have a dedicated cable for it? I've got some Atari 2600 DB9 joystick extension cords laying around that'll literally hook right into the C128's RGB out and a 1084's in. Just wondering if I may be so lucky not to have to hack this up or what :-)
I wouldn't do that if I were you, there is an off chance your monitor will blow up if you do. Pin 7 has composite video on it.
http://www.hardwarebook.info/C128_RGBI Break off pin 7 on the cable's male connector and you will be safe, if the cable has all wires. Still you would be better off with a shielded cable. I doubt that extension cable is shielded.
