MiSTer FPGA Forum

Hi all,

I'm wondering if it could be possible to "zoom" the MiSTer HDMI display, in order to display in full-screen a smaller area of the core frame buffer ?

For example, MSX 1 games are using a 256*192 pixel area to display things, but the MSX core outputs a bigger area with 240 lines. Which is normal: the extra lines are the "background color" - but nothing interesting is usually displayed here (unless for demos or rare games using scanline effects).

I'd like to remove those unused lines and zoom the interesting part to full screen while keeping same aspect ratio. I tried to play with the video_mode and custom_aspect_ratio_1 options, but no success so far.

Another option I guess would be to use the analog output of the MiSTer and connect it to an OSSC, but maybe there's a simpler way to do that ?

I don't think we have any sort of custom cropping as a core mister feature at this time. Some cores have specific cropping for known common sizes, though, such as Neo Geo.

If I understand the OSSC documentation correctly, I think your display has to "play along" with the OSSC to be able to resize the screen. Otherwise, I think you are at the mercy of any zooming options your display may have.

Thanks for the reply hash2fpga

My current undersanding so far (after reading MiSTer Wiki) is that using my OSSC instead of the built-in HDMI converter should not have a bad impact on lag / latency, as there's indeed an existing delay on MiSTer. I'll just build me a VGA to SCART cable and hook it to my OSSC that has a bit more controls on the HDMI scaling, with still very low lag. Maybe the MiSTer HDMI conversion could be improved one day to match OSSC (OSCC is open source, maybe some parts could be imported ) ?

Appart from that, I must say that I'm totally amazed by the MiSTer I was out of emulation during almost 15 years, collecting real consoles and arcade PCBs. I recently built me a RetroPie/RetroArch setup, and that was already definitively great: easy and unified game selection, reduced latency, no hickups on scrolling, etc... But the MiSTer really looks like the next big thing in emulation or simulation

Now that I'm experimenting other cores, the "Hide Overscan" option of the NES core is exactly what I was looking for. Ideally it could be refined (something like Crop Left, Crop Right, Crop Up and Crop Down), and be specified per-game (like in RetroArch).