I started down the path that it may be that KOA needs different hardware specs (i.e. (If you hit the coin switch you will hear a inserted coin when the screen first goes black, then it becomes unresponsive just before it reboots) The system boots up, you see the cursor, it shows a DOS window with KOA in the title bar and seems to load the KOA executable but then the screen goes black and reboots. With the KOA hard drive and key installed in the sysetm. (Hook it up to a computer monitor, same story but never goes wonky.) The unit goes through the boot, you see the cursor, the screen goes wonky (higher res then a tri-mode Nano monitor) then reboots. With the orig hard drive (it didn't come with any usb key) The X2 unit specs are P4 3.4ghz 512MB GRA X1600 Pro (ATI Radeon) I have an Aquarian Age Alternative Satelite X2 unit, a hard drive and key for KOA Reg A and a SEGA Naomi I/O Board Rev B. I am up a creek at the moment and can't tell if I am troubleshooting a faulty X2, config or game issue. Has anyone had luck running different games on the same Taito X2 system?