Finally got Konami GT - Red Fighter (rf2) to show some signs of life. Apparently it wants IRQ 1 & 2 swapped for some reason...
Also started hooking up sounds, removed the hack I had to get the gx400 games to skip the z80 check, improved the speed/quality of the background drawing routine (the games now take about 6-8% cpu on my 1.8 core duo, rather than 13-15%), and hooked up most controls -- the only thing without are the driving games that need analog inputs.