MiSTer FPGA Forum

Hi,

I have a Mister system with SD-RAM and run the Minimig Core. For a particularly gnarly level in one game I’m toying with the idea of beating it using joystick playback. This needs to be synched with the frame rendering of course.

I’ve been sifting through github and especially focusing on the io board, and found - as I understand it - vsync at pin 19 of GPIO1. See https://github.com/MiSTer-devel/Hardwar ... rd_6.1.pdf

So I run the system via HDMI, and get video output. But probing pin 19 with my scope didn’t lead anywhere. There’s just some ~1V flatline showing.

Is there anything I’m overlooking? I tried searching this forum and read the instructions. From those I would’ve expected the VGA(ish) output to always work, and that HDMI is a post-processing thing (possible buffered).

Any pointers are very welcome. An adjacent subject would be direkt (non-USB) joystick input into the MiniMig core. I haven’t found anything there. I would be comfortable implementing the blister box serial protocol, if need be.

Thanks for your consideration & this amazing project. It has provided hours of fun already, and with the PSX support shaping up a direly needed way to play WORMS 1 after the failure of our PS3 fat with emulation in it, will see even more.

I'm still researching and trying to figure this out, so I'm bumping this. Hope that's ok.

To enable VGA output including sync signals a specific pin needs to be grounded.

It is specified as pin AH_27 VGA_EN in sys_analog.tcl https://github.com/MiSTer-devel/Templat ... og.tcl#L43

The image here says that that pin is GPIO1 pin 10. https://www.rocketboards.org/foswiki/pu ... in-out.png

Amazing! I had thought something like that and tried to work it out from the schematics. I just gave it a test & low (pun intended) and behold: I’ve got vsync! Thanks a million.