nesdev.org

I just rewrote my CPU from the ground up, to make sure there were no bugs. It's also 100% cycle-accurate now, including the instructions that add 1 cycle when crossing page boundaries. Every read/write triggers 3 PPU cycles. It's hardcoded to 3 right now, but I'll add the option for switching to PAL...

I do only set v on the pre-render line when rendering is on. I have all of my rendering code (except for the vBlank flag set/reset and the NMI interrupt) inside an if statement that checks if rendering is enabled. Rendering is enabled if bits 3 or 4 are set in PPUMASK. It still increments the dot an...

Here's what the problem is. I was unable to solve it correctly, but I fixed it temporarily with a hack. When leaving the title screen and entering the first level, the games must replace the nametable data. They don't finish writing the nametable data before the end of vBlank. Once rendering starts,...

I have a problem that I can't figure out, and it's driving me absolutely crazy. :x If anyone could help me, I would very very much appreciate it. I started emulating the v, t, x and w registers for the PPU. I'm not yet using them during rendering at all. I'm only using them when reading or writing $...

This is awesome! I love voxels. I started a small Minecraft clone, and made a 3D sculptor using the marching cubes algorithm. I tried to think of other cool things to do with them, but failed to come up with any ideas. This is a great idea though. I really like it

Ah, that makes sense. I'll add a check to make sprites with an x position of 0xFF clear. And yeah, it's doing the nametable and attribute fetching correctly, where it wraps around to the next scanline. I just didn't do the same with the pattern fetches. That's why it draws the correct tiles on the l...

Alright, that's what I thought. Getting the timing right for that is gonna suck. And the big day's finally here guys! I added controls and I can now play games on my emulator :D I was too lazy to fix the leftmost 2 tiles. It's just a matter of adding an if statement to check the dot an increment the...

That's cool. I live a couple minutes outside of Madison, so it's that's only an hour drive. Are there people there that would be interested in hiring a programmer? Unfortunately I don't have a degree yet, gonna go to college next year.

So that's not how splitscreen works? I don't know anything about scrolling yet. Once I do controls, I'll do scrolling. Is Excitebike a good one to start with? My rom gets to the demo screen and doesn't show sprites, but I'm guessing that's because I haven't added scrolling yet.

I've done my PPU timing exactly how the diagram shows, which is important for things like splitscreen right? Does the game just count cycles from vBlank and change the scroll half way through the scanline? And good news, I got sprites working last night! Was much easier than I thought it would be. I...

Impressive. I like it. I'm also working on an RTS, but it's for Android.

I graduated high school 2 years ago. Had a good but temporary job at a utility company. Got laid off. I'm gonna go to college for computer science. Not sure where I'm gonna go yet, though.

"Super Mario Bros. is probably the hardest game to emulate among the most popular NROM games, which are generally the first targets against which an emulator author tests his or her work. It relies on JMP indirect, correct palette mirroring (otherwise the sky will be black; see PPU palettes), s...

By writing to CHR-ROM, I don't mean its SUPPOSED to be doing that haha :wink: There's a bug in my emulator somewhere causing it to do that. I'm not sure if it's a CPU or PPU problem. I tried for a while to find what's causing it, but it's not easy to track down. My emulator throws exceptions when wr...

Yep lol. I had to leave right away, so I didn't have time to fix it before I posted the screens. I started working on sprite evaluation, so I should have sprites showing up soon. Probably by tomorrow if I feel like programming later tonight