anyone has a link for the Bgg or Bbb chip
BBG stands for BeagleboneGreen and it is a mini computer. You can buy one at seeedstudio.com and elsewhere in electronics shops.
I recommend using BBG, but if somebody already has BBB then try that one first.
So, is Arvid the right thing for me?
It's hard to say, depends on your expectations. For example ArvidMAME currently doesn't support accelerated 3d rendering, so new 3D games will work way slower than you might expect. If you are into emulation of that kind of machines you'll need more powerful computer. It's not impossible to fix that, but I didn't have time / motivation to implement it. If you happy to use 2D machines, especially those with non standard resolutions and/or refresh rates (for example irem games, cave games, toaplan games etc.), then it might be the right thing. But if I understand well GroovyMAME supports these things too, am I right? Arvid can be also useful if you plan to use notebook or mini pc for the emulation.
Can I create custom horizontal resolutions with it or does it restrict me to those listed in the specifications?
Yes you can, the firmware and rest of the software is open source with non restricting license. Mind you, if you'll be modifying the resolutions it's better to test on some multi-sync monitor (and oscilloscope as well) first, just in case a mistake in resolution parameters would damage your regular monitor. Realistically a maximum resolution you will get on BBG using ARVID is around 720x480i or 360x480p (will need a better monitor than 15kHz though for the latter).
Does it work in Windows with any software (version of MAME)
Currently there is only ArvidMAME that supports the hardware (AFAIK), but anybody is free to add support for other emulators as well. As I wrote above, the source code is open an non limiting (MIT license). ArvidMAME is ported to Win32, Win64, Linux32, Linux64, OSX64, ARM Linux32. The Linux ports are also supported in headless mode so they don't need Xorg (graphical/windowing interface).
is it required to reprogram/patch the programs for it?
If you want particular software to output video signal on Arvid, then yes you/somebody has to reprogram it.
does Arvid output a DC coupled or AC coupled video signal
The video signal is generated by BBG which operates on DC. GPIOs of BBG produce 3.3V DC digital signals that are converted via resistor network into analog signal. The output voltage of white colour measured when the TV is disconnected is ~1V. The TV (when connected) reduces the incoming signal voltage by its internal voltage divider (usually resistor of 75 ohms).
I'm working on an adapter to make consoles work on my cabinet...
The following page describing video pin-out of various game consoles might be useful:
http://members.optusnet.com.au/eviltim/gamescart/gamescart.htmSorry to moderators, I guess we are getting slightly off-topic in this thread, feel free to move it somewhere more appropriate.