A hantarex 9110. When I say direct connection what I mean is I've spliced the wires near the monitor and attached a vga cable. This is how I used to run it back when I had an arcade vga before I upgraded to the ati 4xxx and jpac combo. However I can't exactly tell you what wire went where as it was so long ago. I followed a guide on arcade controls or possibly the one on ultimarcs site. Quite likely I've combined h and v sync together as Andy suggests
Perhaps the jpac does something else other than just boost the signal? But as mentioned if I run it via the jpac and choose any non-interlaced mode it's perfectly fine.