Well, this is a huge topic. Where to start?
First off, you should not have purchased anything with MAME in it. It's against the MAME license to sell it and the person who sold it to you violated that license.
Why are you changing the computer in the cabinet at all?
I'm assuming you have a standard resolution 15KHz arcade monitor in your cabinet.
If that's the case, then the original computer was probably set up with one of the following...
1) Ultimarc ArcadeVGA card - this is a special card for arcade monitors
2) An older ATI Radeon card with CRT_EmuDriver (custom drivers) and GroovyMAME
3) Soft15KHz combined with a compatible video card
Based on the fact that you saw the split screen during boot with the old computer, I'm guessing that you had either #2 or #3. The ArcadeVGA has a special BIOS that will display normally during boot.
The reason you're seeing a split screen is because of a device called a J-PAC, which is another Ultimarc product. This device plugs into your cabinet's JAMMA harness and converts button presses and joystick movements into keyboard key-presses for your PC. It also feeds the video output from your PC's video card into the JAMMA harness so that it displays on your arcade monitor. One of the features of the J-PAC is that when it detects an out-of-range signal for your monitor, it will split the image on screen to protect your monitor from damage.
Sadly, you can't just drop in another computer and have it work. The video card must output a signal that's compatible with a 15KHz arcade monitor. Note that the J-PAC does not convert the video signal. Check out this thread for some video options...
Also keep in mind that if you plan on using a newer version of MAME, many of your old ROM files will need to be updated.
GroovyMAME support forum on BYOAC
CRT_EmuDriver - ATI Radeon Catalyst video driver for GroovyMAME
tankadin.com : tank + paladin = tankadin
Edited by krick (07/07/12 09:02 PM)