Відео

@@daewvey Thank you!

The actual approach used in the hardware here is pretty tricky. There's a clever dance the PPU performs in order to make the most of limited hardware. Before any scanline, the PPU will determine which sprites will be drawn on the next line. The information for the 8 winning sprites for that line are placed in some internal memory on the PPU (often called secondary OAM). When the PPU is drawing to the screen, it is loading internal shift registers based on what will be drawn for the next 8 pixels. It then shifts out these buffered values, and selects from either this (possibly empty) sprite or the background. This process is often called "sprite evaluation" if you want to look for more details.

@@EmulationOnline thanks I have trouble in my head imagining the speed of how this happens.. I mean the timing at these speeds is crazy especially with no buffer--so basically it’s using the shift registers to make a continuous stream…. Per scan line then usiwa the blanking period to setup the next scan line… as long as ur fast enough and can keep the timing this avoids needing a whole page of buffering and vram

@@sodapopinski9922 Yep, the shift registers help render at high speed. Each byte from vram has info for several pixels. Fill the shift register from vram, then shift the bits out just as they are needed for rendering.

@@EmulationOnline is it in code we keep track of the vertical bits and use the shift register to keep track of the 8 bits horizontal in an 8x8tile So basically I’m wondering it knows what tile it wants how does it keep track how many lines from the tile have been drawn is there a register to keep track that you he system checks every scan line

I've seen a lot of different names applied to this. The key idea is that 2x2 tile areas share a palette, and 4x4 tiles or 2x2 of those earlier chunks are represented per byte in the attribute table.

Thanks!

Thank you!

@@bonciutalentadv7599 Thanks, glad you're enjoying them!

Thanks! Make sure you check out the other videos in the series. And more are in the works.

Very cool. How did tv output work on the apple 1?

​@@EmulationOnline I apologise) of course, not TV output, but composite video to be correct)

Glad you liked it! I'm going to keep making these videos, so maybe one day :)

Thanks for watching!

Thanks for the suggestion! I certainly want to avoid ambiguity or misleading. I try to make sure any numbers are written on screen, to help remove any questions as to what I'm talking about. My hunch is that people would prefer to read these numbers anyway. I'll try digit-at-a-time pronunciation in the future. The main downside is that it takes longer to communicate.

Thank you!

Thanks for pointing this out, it should be fixed in a bit. *edit* Fixed now.

Oh, thanks for calling this out. For anyone else confused, I mean roughly equal or approximately equal. I haven't done much lua. I didnt realize it means not-equal there, which is actually the opposite of what I meant.

Yep definitely confused me initially too.

Welcome! I haven't built a NES emulator before, but built emulators a for a few other simple systems. For the videos, I make sure to describe parts that are already fully working. This helps ensure my descriptions are correct.

Thanks!