nesdev.org

So, if I'm understanding it right, the SNES allowed cartridges to remap pretty much everything and each game had a completely custom configuration? WTH Nintendo? This starts looking worse than the situation with NES mappers. I wonder if this was Nintendo's idea to thwarting copiers, since something ...

Isn't the main difference that the clock speed used to access both is different? (used by Nintendo to allow starting with cheaper slower ROMs and then go with faster ones once they price dropped later in the SNES lifetime) Or am I getting confused with something else?

Just now looking at this thread. I have no idea what I'm talking about. That being said, here is a solution used by Genesis homebrew developers: https://github.com/sikthehedgehog/mdtools Nice but unfortunately it looks like it's specifically for graphics. I'm no expert, but a codec made for graphics...

In other words, claiming that the 68000's inferior IPC is a good thing. That depends, when it comes to handling large numbers the 68000 is better, and that's a place where a lot of abuse happened (Treasure's complaint about the SNES not being able to pull off things like Alien Soldier probably has ...

http://ask.slashdot.org/comments.pl?sid=3032243&cid=40907325 You might be tempted to attribute this to some mystical "Blast Processing" capability of the Mega Drive/Genesis chipset. But Blast Processing is just Sega's term for DMA-assisted copies to VRAM during vertical blanking time. ...

I have no idea how the SNES PPU works internally at all, but if it's anything like the Mega Drive, it doesn't cache the tilemaps at all but reads them on-the-fly as it rasters. No idea if the mosaic data is cached, though (which could be a possibility, especially since it can work with non-power-of-...

I think he meant "screw up" as in "make it behave in a completely different way from what it was intended" (ideally in a stable way). As I mentioned before, for what we want we could easily work around it by just changing the vertical scroll every line. If you wanted to get the s...

I'm not sure what you don't understand. You agree that if you save VRAM by using mosaïc, this will make pixels 4 times bigger, and only the even or odd bits from the input tile will be used. However this has no purpose if you can't re-use those even/odd bits for the second BG layer. This will mean ...

If you want to save RAM using mosaic it'll be complex as the 4BP tiles and 8BP tiles would have to share the same memory location ! I really don't get this one, period. Do you mean that both tilemaps have to share the same table or what? Because if you mean that the tiles share the same base addres...

In the 256+16 layers, is it possible to have the 256-color layer as direct color and another paletted background sum-blended onto it? Seems so, direct color applies only to BG1 (and works in mode 3), BG2 is unaffected. I suppose you could do RGB 3.3.2 on BG1 (not 4.4.3 since the extra bits have per...

However there is no mode with mulitple 8BP BGs, therefore you'll have to deal with mode 1 or mode 2's 4BP BGs. Not necessarily. Let's assume we went for the same amount of precision - RGB 3.3.3 (512 colors). Yes, we could do better, but let's start there. Each RGB component would require 3 bits. So...

Mode 4 has the "offset-per-tile" mode that mode 3 lacks. I really wasn't taking it into account, so I doubt that's an issue. You can't save VRAM by using mosaic, period. Remember how tiles are stored in memory, each byte is a "bitplane" of 8-pixel. What you'd do by setting the m...

2 tilemaps ? Blending ? What's the point ? Get past the 256 colors limit and retaining control over every RGB component. The idea would be to use additive blending (so the components from both layers are added), then put two components in the 256 color tilemap and the remaining component in the oth...

However with mode 3 or 4 you have 1024 tiles, and if all of them are defined it takes exactly the entiere 64k VRAM. Therefore you'll have to reserve at least 1024 bytes for the map, but then 63k of RAM, or 1008 tiles. Because at most "only" 32x30 = 960 tiles are visible on the screen, it ...

What are you talking about ? The SNES' mode 3, 4 and 7 can have 256 colour BG. The palette is 256 colours anyways so you can only have more by changing the palette midframe with HDMA, which is possible, as Secret of Mana does it. Wait, so it isn't just mode 7? Then the blending idea would work beca...