6502 NES PPU Graphics Chip Hacking

http://www.xgamestation.com - In this video I am interfacing with a Nintendo GPU called the PPU. I also display a simple little demo with ripped tiles from mario.

Category:

Gaming

Tags:

• 6502
• NES
• nintendo
• gpu
• ppu
• mario
• game console
• video generation
• ntsc
• video games
• xgs
• super mario brothers
• uzebox
• arduino

[gimp3695]

Wow, you guys are going way in more depth than I originally planned when I did this project 3+ years ago. My whole point of doing this was to build my own 6502 computer and learn more about computer architecture in a fun way. Since growing up in the age of the NES I've always had a respect for what Nintendo did and I wanted to know more about it while breadboarding my own computer. That is all.

But I am enjoying the conversations you are having.

[3mustardMoNkEyS]

Do you have a blog or some documents for interfacing these chips or is it the same interface method like with an original 6502?

[gimp3695]

@3mustardMoNkEyS back when I worked on this...over 3 years ago...I found lots of literature online of the PPU chip. I even found some of the original schematics for the NES. The 6502 however I just designed on my own.

[sz42781]

Theres only one problem! You have major league baseball in the nintendo and you have super mario on the screen.

[gimp3695]

@sz42781 Well the game in the console is yes MLB (came with it from ebay) but I ripped the mario graphics from an emulator ROM and stuck it into my 6502 image.

[TheUnbiasedGamer]

Yeah what he said! O.o

[nopochoclos]

Hey, nice video and hack, i am a computer and video console colector, i have a lot NES clones motherboards, and i see , these have a 6502 compatible family proccesor, this maybe run on Commodore 64? i think maybe has more instructions but i want to know if i can revive a Commmodore 64 with Family Game (Nes Clone) 6202

[wisteela]

Very impressive

[forlorndivinity]

@gimp3695 You're a lot like me. I'm not sure if your friends and family and people you know sorta frown upon you for "hurr durr why are you working with such old hardware it's all about next gen lololol" like they are with me. As a kid I remember always being fascinated by the way games were and wanting to learn how to make my own NES and SNES games.

I hope to see more great stuff like this from you! Keep it up!

[localhbci]

Also want to add one more thing as I've been thinking about it: such techniques are not designed into the chips so it's possible that some of them may not be noticeable that way. Still, it would require such an accelerator for the NES to make use of it but the possibilities are still worth exploring.

[localhbci]

Let me give you a C64 example. There is a software graphics mode called FLI, which basically changes the pointer to color memory every scanline, to get 4x1 (multicolor pixel) color cells instead of 4x8 as one would normally. However, there is a 3 character wide bug on the left hand side of the screen. With a SuperCPU, it can stuff values onto the bus for the VIC-II to read. More indepth explanation in an article in "C= Hacking #21", Google it.

[3GenGames]

Makes some sense, but even if you do that, you will still not know the specifics behind them. With Visual6502 emulating all those chips, soon the PPU will have images of the quality to do that, as it's already decapped just not emulated as the decapping wasn't 100% perfect, although right now I believe it's being decapped again.

[localhbci]

@localhbci I will clarify, by "CPU cycle" I mean by the equivalent of every normal NES ~1.79MHz CPU cycle, of course. Similar to how the SuperCPU for the C64, running a 65816 at 20MHz, allows hitting VIC-II regs on every 1MHz 6510 cycle (and the CPU will actually block until the 1MHz cycle hits so you can just more or less spin on a loop and spew values at VIC registers every 1MHz cycle if you want).