Questions about AO486 and beyond - special arcade project

[ggvicviper]

Hi all, I’ve been hearing about the MiSTer for a while, and I had a really wild idea last night just before I fell asleep.

So, I’ve been wanting to do homebrew arcade development for years, but the best/easiest solution I’ve come across is the UzeBox JAMMA. The problem with that is the hardware is far too limiting for anything I want to build (and I’ve built two projects on it already), and the community is small and dying. Using Raspberry Pi’s basic tools always leaves me with dealing with the issues of Linux (including difficulty with Vsync) and the general wacky hacks needed to do games at 240p. RetroPie and the like are good for what they are, but Pi isn’t working out, and I’ve never been a fan of the platform anyway. And the more I’ve kept hearing about the MiSTer, the more I wished I could build a game for it.

Last night, I had a thought. I know there are a few JAMMA connectors for the MiSTer. What if I could build a game in DOS, have the MiSTer run a DOS core and boot to my software in autoexec.bat, and have IO done through JAMMA at 240p/15KHz? I know original DOS PCs using Mode 13h only do 31KHz VGA, but it’s sounding like you’re able to get these on RGB monitors at 15KHz, which would be exactly what I would need for a true arcade/JAMMA setup. Building a game to use ModeX at either 320x240 or 256x240 seems like an optimal solution to build homebrew arcade games on that core, since that ensures 60Hz refresh rate.

So, I guess my questions are:
1. Is what I’m saying doable/possible, or am I way off the mark?
2. If this is doable, what would be the recommended components I would need to get?
3. Also if this is doable, what settings would you recommend me running the system on?
4. Finally, if anyone has experience with any of the JAMMA adapters out there, do you know if this would interface with the ao486 core through keyboard?

[softtest9]

I would suggest that you experiment with existing "240p" games first and see how comfortable you can make the experience. A game can be added to your DOS autoexec.bat, giving you an "autoboot" experience. Does the video chip in ao486 support 15khz? If not, maybe the image would need to be downscaled by MiSTer's scaler.

As for JAMMA, I know that some people have been experimenting with it, but no idea how well it works. I only have LCD.

Everything you want should be doable, but it does sound like a huge project.

[flynnsbit]

Yes to all of that.
I built a Mortal Kombat 2 VHD that does everything you said and is setup to use the MisterCade Jamma and a 15Hz monitor. That image is on archive.org if you want to see how I did it. I even hid the dos boot with the Mortal Kombat CMOS boot screen.

https://www.youtube.com/watch?v=-kW0GeQ5_nM

https://www.youtube.com/watch?v=-adhYSjb6UA

[ggvicviper]

Yes to all of that.
I built a Mortal Kombat 2 VHD that does everything you said and is setup to use the MisterCade Jamma and a 15Hz monitor. That image is on archive.org if you want to see how I did it. I even hid the dos boot with the Mortal Kombat CMOS boot screen.

https://www.youtube.com/watch?v=-kW0GeQ5_nM

https://www.youtube.com/watch?v=-adhYSjb6UA

Awesome - I think this is exactly what I’d need. Which components did you use? It looks like the USB hub and the base DE-10?

[flynnsbit]

Yes to all of that.
I built a Mortal Kombat 2 VHD that does everything you said and is setup to use the MisterCade Jamma and a 15Hz monitor. That image is on archive.org if you want to see how I did it. I even hid the dos boot with the Mortal Kombat CMOS boot screen.

https://www.youtube.com/watch?v=-kW0GeQ5_nM

https://www.youtube.com/watch?v=-adhYSjb6UA

Awesome - I think this is exactly what I’d need. Which components did you use? It looks like the USB hub and the base DE-10?

I'm using a beta version of the Mistercade. https://www.youtube.com/watch?v=9-212r6kKC8
https://misteraddons.com/products/mistercade

[ggvicviper]

Yes to all of that.
I built a Mortal Kombat 2 VHD that does everything you said and is setup to use the MisterCade Jamma and a 15Hz monitor. That image is on archive.org if you want to see how I did it. I even hid the dos boot with the Mortal Kombat CMOS boot screen.

https://www.youtube.com/watch?v=-kW0GeQ5_nM

https://www.youtube.com/watch?v=-adhYSjb6UA

Awesome - I think this is exactly what I’d need. Which components did you use? It looks like the USB hub and the base DE-10?

I'm using a beta version of the Mistercade. https://www.youtube.com/watch?v=9-212r6kKC8
https://misteraddons.com/products/mistercade

Ah, it’s an all in one! This is perfect! I’ll try to get this when it returns back to stock. Thank you for the info.