nesdev.org

Okay, found a reference that isn't the dev manual (not as explicit about the circuit layout, unfortunately): http://forums.nesdev.com/viewtopic.php?f=12&t=5964&hilit=Additional&start=45#p103957 GSU Memory Map (at SNES Side) This is more or less as already known. The 8K at xx:6000h-xx:7FF...

koitsu wrote:Re: 8bpp available in mode 3, mode 4, and mode 7: this is correct.

For the SNES, or for the Super FX?

8bpp can be used for both mode7 and mode3/4, it depends on how you upload it to vram (port $2118 byte transfers interleaved or word to 2118/2119) and how you build your map. You sure? How would you account for packed-pixel vs. bitplane? Well, technically the GSU is wired directly to the cartridge (...

Isn't 8bpp (mode 7) packed instead of planar? I can't find that data in the manual. Did Doom use Mode 7? I saw a reference that said it didn't. The SNES has two other modes with 8bpp layers, and they're planar. Plus I don't see anything in the manual that indicates radically different behaviour whe...

I have a few technical Super FX questions, but I'm not sure if they're the sort of thing one would need to ask one of the Argonauts, and anyway they partly overlap Sik's questions. Does anyone happen to know the answer to these? 1) What are the absolute hardware bottlenecks on blitting (using PLOT w...

I could send you some money via PayPal, enough to cover the costs of a Super Everdrive + S/H and you could get it yourself. Sure, that works. I've PMed you. I'm not actually all that worried about trustworthiness - you do look like a reliable character, as much as an online presence can. It's mostl...

Re: black flecks: which video are you referring to (there are "black dots" in all of them in some manner of speaking ;-) )? I'm going to assume you're referring to Pan's demo -- if so, they're the same height as the "white/grey flecks" in mtest_scroll and mtest_reverse. My gut i...

Thanks to both of you! If I had the hardware, or enough free cash to obtain it, I'd test this stuff myself, but I don't... That "black static" is worrisome. Apparently even the sprite layer glitches briefly - but it's probably not very noticeable on an overlay as dark as the one I'm planni...

...okay, so it looks like Sik called it. Apparently you can change from Mode 7, but not to Mode 7, at least if the line doesn't start in Mode 7. Unless there's a bug in my code that doesn't trigger in higan... Also, something funny is going on with the timing; it doesn't look quite the same as in hi...

How narrow do you think I can get the garbage area? Or should we wait for better video? I don't know if running the game logic in VBlank is a good idea in this case. Even with a 144x192 playfield, after accounting for all the stuff that needs to happen via DMA, plus related maneuvering, I figure I'd...

> You can't trigger NMI manually, can you? Sure you can. Push P and your return address onto the stack, and then JML to your NMI vector routine =) Well, yeah, it sounds silly when you put it like that ... I guess what I was hoping for with that question was something I could poke with HDMA, since a...

While we're waiting... Is there a preferred method of extending VBlank while the IRQ is otherwise occupied? I was thinking of using a couple of HDMA channels; one to toggle the display and one to hijack the interrupt (which would probably have to be in RAM). This would allow the mode change interrup...

Okay, apparently it is possible to speed-write to the scroll registers by splitting the values and doing two 16-bit writes to the first one. I could be misunderstanding what's going on, I suppose... I was going to use DMA, but I can't get it to work without having to set up the registers all over ag...

> or the fact that actual code is running in between BGMODE writes... You really don't have time for this sort of thing. Even the fastest possible instruction is equivalent to three PPU pixels. On average it's more like six pixels per useful instruction. I don't mean trying to fit in code during th...

Hmm... It looks like my test program has about three tiles worth of garbage, but the Anthrox demo seems to have five. I hope this has more to do with the HDMA "plasma" effect than the fact that the Mode 7 layer is actually doing something, or the fact that actual code is running in between...