August 30, 2019 at 1:19 PM #27741
Sorry if this has been asked before. But I’m using the OSSC with my Genesis, and using optimal timings for 256 & 320 res modes. I wanted to know of the OSSC can, or could be able to, auto switch resolutions when they are activated within the game? Cause Sonic 2’s special stage does this, and i use 320×224 for the rest of the game, and when that stage kicks in, the visuals look off to me, cause it goes to 256×224. Idk if something can be done where on the OSSC, you have profiles in a certain order where the OSSC will jump to said resolution and back?August 31, 2019 at 7:33 PM #27761HarrumphParticipant
Not possible. AFAIK, a change in horizontal resolution in an analog signal is not reflected in any parameter of the signal itself. So there is no way to detect it by the digitization chip. (The OSSC determines modechanges (eg 240p to 480i) by linecount and vertical frequency, and neither changes with different horizontal resolutions)September 1, 2019 at 12:55 AM #27762nmalinoskiParticipant
This sort of thing is probably best suited for an internal scaling solution, but, if there’s a pin on an IC somewhere for pixel clock, and serial remote control/configuration makes it into the OSSC firmware, then someone should be able to build a mod board for an affected console that reads vital AV information from the console and somehow transmits it to the OSSC, which could decode those signals, making automatic timing configuration possible.
I’m no electrical engineer, but if the pixel clock could be read from the board, I imagine a mod board in an affected console could monitor that pin, and, when the pixel clock changes, it could modulate a unique, identifiable instruction and the pixel clock value and mux the result on the sync pin. The OSSC could then listen for that pixel clock instruction and reconfigure its timings by itself.
I’m not all that familiar with video frames, but, if there’s blank lines or a metadata portion (I’m still not sure how my Trinitron knows and automatically adjusts when my Xbox has been switched to widescreen mode), and it makes more sense to do so every frame, it might be possible to hijack unused portions of the metadata or frame to transmit the pixel clock instruction.September 3, 2019 at 6:51 PM #27778
I love the OSSC, but I’m disliking the Genesis with it more and more, I own a model 1 which I csnt fully remove jailbars with bypass boards and smd capacitors, and then there’s the resolution changes throughout games. I dont want to purchase the Mega SG, because I want my model 1. My SNES 1CHIP-03 is the only console I’ve got looking magnificently with my OSSC. I figured since 240p/480i was able to swap via the OSSC, that what I’m asking would do the same. Thanks for the replies!September 4, 2019 at 9:24 PM #27785marqsParticipant
I’d recommend using Generid 4:3 mode with games that toggle between resolutions. Have you cut off subcarrier trace (preferably right after VDP output)? That should remove most of jailbars.September 5, 2019 at 12:03 AM #27788
Thanks for responding marqs, yup pin 50 from the VDP has been cut. I originally tried generic 4:3 and loved how everything looked, but then I learned about optimal timings and I dont want to go back to generic 4:3, cause OT looks like an emulator with my snes/genesis! But if you’re telling my only option is to stick with generic 4:3 for genesis, I may just do so.
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