480p and Other Resolutions for Saturn Homebrew

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slinga

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I would like to test a few alternative resolutions on the Saturn. I found this thread: Progressive hires test demo? which says that the Saturn can output 480p.

1) Is there any homebrew source code available that supports 480p? Charle's MacDonald's C4-2006 demo doesn't appear to include source code.
2) I understand RGB Scart cables are required. I'm assuming the HD-Retrovision are also functionally equivalent?
3) Would modern TVs actually be able to display this? From what I understand it the resolution is 480p@15hz.
4) If a modern TV cannot support this resolution, would it work with an OSSC or Framemiester?
5) What other resolutions are possible? 720p? 1080i?

Thanks in advance.
 

Ponut

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v1.JPG
[Above: VDP1]

Due to the frame buffer size restrictions of VDP1, double-density interlaced modes must have the command list processed twice for the same screen. The first screen is the image of odd coordinates, the second screen is the image of the even coordinates. When combined, they form a true image with doubled vertical density (resolution).

VDP2:
v2.JPG



Capture.JPG

The long and short of it is:
_ONLY_ VDP2 can operate at 480p, and it can _ONLY_ display one background layer at this resolution, with NO color calculation,.

VDP1 cannot operate any progressive scan res more than 240 pixels [NTSC] 256 pixels [PAL] high.
fafling and mrkot would know more.
 
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fafling

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Why do you say that special high res is limited to 16 bpp pixels ?
Edit : The color ram is limited to rgb 555 colors, but the pixel format of the NBG can be anything that fits in VDP2 VRAM, except 32 bpp (p. 60-61 of VDP2 manual for "exclusive monitor"). The name of this mode is inconsistent in the manual.
 
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Ponut

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Why do you say that special high res is limited to 16 bpp pixels ?
Edit : The color ram is limited to rgb 555 colors, but the pixel format of the NBG can be anything that fits in VDP2 VRAM, except 32 bpp (p. 60-61 of VDP2 manual for "exclusive monitor"). The name of this mode is inconsistent in the manual.
I forgot that 24bpp RGB layers were possible.
 

fafling

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Another inconsistency is that the manual lists pixel formats for NBG2 and NBG3 in exclusive monitor mode (2nd table p. 61), but those layers are not supposed to be displayed in that mode.
 
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