Neat to be able to run more with PSRAM4. On one of my old projects in this thread here I have a 4 bit PSRAM (and parallel LCD or VGA) plus USB so it might be a candidate for some retro gaming one day too. The LCD is 800x480 however so is probably not that nice a resolution to target. https://forums.parallax.com/discussion/169431/p2-voyager-project-was-new-toy/p3
@rogloh said:
Neat to be able to run more with PSRAM4.
It's not a PSRAM4-exclusive fix, that one's just the absolute worst for ROM->VRAM DMA. Wolf3D does tons of WRAM->VRAM, that one was busted regardless of RAM speed. The new DMA code properly grabs the ROM data for the upcoming transfer block in one go, so a lot less overhead on that.
On one of my old projects in this thread here I have a 4 bit PSRAM (and parallel LCD or VGA) plus USB so it might be a candidate for some retro gaming one day too. The LCD is 800x480 however so is probably not that nice a resolution to target. https://forums.parallax.com/discussion/169431/p2-voyager-project-was-new-toy/p3
800x480 should be fine, I can do that on HDMI, so parallel LCD shouldn't be a problem on that front. You just get big bars on the games.
Hmm, so I can find 2 games that definitely don't work anymore with the new DMA code: Donkey Kong Country and Jurassic Park. Former is a big pain, I just fixed that one in beta07!
Also, there's timing problems in Demon's Crest that are still not fixed with this. Though I'd assume that's regular "where does the IRQ go" type problems.
EDIT: Fixed it, just went into an infinite loop based on difference of opinion on when exactly events should happen between DMA setup and everything else.
Appears that actual 480p resolution games can gain a lot. Not clear about these games that are more like QVGA though.
Does mention sega genesis though, so maybe...
Nothing worthwhile. The HDMI output from the P2 is already as good as it gets.
These kinds of things tend to just attempt to apply an FXAA-type algorithm to smooth edges.
Comments
Neat to be able to run more with PSRAM4. On one of my old projects in this thread here I have a 4 bit PSRAM (and parallel LCD or VGA) plus USB so it might be a candidate for some retro gaming one day too. The LCD is 800x480 however so is probably not that nice a resolution to target.
https://forums.parallax.com/discussion/169431/p2-voyager-project-was-new-toy/p3
It's not a PSRAM4-exclusive fix, that one's just the absolute worst for ROM->VRAM DMA. Wolf3D does tons of WRAM->VRAM, that one was busted regardless of RAM speed. The new DMA code properly grabs the ROM data for the upcoming transfer block in one go, so a lot less overhead on that.
800x480 should be fine, I can do that on HDMI, so parallel LCD shouldn't be a problem on that front. You just get big bars on the games.
Hmm, so I can find 2 games that definitely don't work anymore with the new DMA code: Donkey Kong Country and Jurassic Park. Former is a big pain, I just fixed that one in beta07!
Also, there's timing problems in Demon's Crest that are still not fixed with this. Though I'd assume that's regular "where does the IRQ go" type problems.
EDIT: Fixed it, just went into an infinite loop based on difference of opinion on when exactly events should happen between DMA setup and everything else.
Curious about what this gizmo would do for Sega Genesis emulator:
https://marseilleinc.com/products/buy-mclassic
Appears that actual 480p resolution games can gain a lot. Not clear about these games that are more like QVGA though.
Does mention sega genesis though, so maybe...
Nothing worthwhile. The HDMI output from the P2 is already as good as it gets.
These kinds of things tend to just attempt to apply an FXAA-type algorithm to smooth edges.
Yeah, think my monitors and tv already do up scaling. Works well on actual 480p or better input. But this is just too blocky to work…
Do wonder though if output were to just one corner of screen, maybe upscaler would work and then maybe could zoom into that area on screen…
You can not squeeze blood from a stone