nesdev.org

So, for objects I want to move at a fractional speed on every nmi, something like 0.5 or 1.25 pixels every time an nmi runs, I'm currently using a second byte where I'm only using bit 6 and 7. I've been messing around with Easy6502 trying to get something working, but I've been running into issues. ...

I'll have to pick up "I am Error". I think it's been pretty amazing what has been done to figure out how all this stuff works.

Thanks for the insights!

Patent databases are online and searchable for the most part: http://patft.uspto.gov/netahtml/PTO/search-bool.html Patents don't really have to describe all the details of how something works, though, only the unique novelties of the part of it they're trying to patent. They're not the best documen...

Somewhere along the lines while reading documentation, I read that all of this information about the NES was discovered through a combination of reverse engineering and studying Nintendo patents. Does anyone have a list of the relevant patent numbers or perhaps links to the patents online? I found t...

In rainwarrior's example he had a .cfg file that laid out the memory and segments. I don't see anything like that in Nova. He uses a bunch of segments like Nova The Squirrel's linker configuration file is called " nova.x " for some reason. Ugh... I should have looked in the batch file. No...

Thanks Guys, I really feel like I'm starting to get this. koitsu that post was really helpful. I feel like you really filled in some of the gaps I had in my understanding. Also, whoever suggested Nova The Squirrel as a better starting point, thank you also. I've been going through that code today, a...

Inside an NES cartridge you will find two ROM chips. One is called CHR, one is called PRG. In the iNES file, these are different sections of the file. One belongs to the PPU (graphics unit), and one belongs to the CPU. The two of these occupy completely different memory spaces ( PPU vs. CPU ). The ...

6502 is one thing, but the rest of the hardware and all that surrounds it is a whole other ball game. I agree completely... basic 6502 programming is super easy, but the way the 6502 (particularly the NES) interfaces with everything is the real challenge. I've been coding professionally for more th...

I'm just using "partitioning" to describe the process of allocating data, graphics, and code to different banks. Gotcha. I've noticed that some assemblers use .org to do that and some use .segment with a keyword that in the case of ca65 is defined in a .cfg file. This came out of rainwarr...

I'm not clear one could even begin to grapple with understanding how to partition things until after you understand how the partitioning works at all. I just searched nesdev for partitioning and nothing came up. I also googled for nes assembly partition and couldn't find anything useful. If you hav...

So ... do you know that your project won't fit in plain NROM? Writing a game at all isn't exactly easy, and it'll be a lot easier to not worry about this extra hardware until after you feel you have a handle on everything else. Writing something really basic was pretty easy. My problem is I'm not s...

For reverse-engineering "stuff", I would suggest browsing over to http://www.romhacking.net/ . It's not just a site containing IPS patches of translated games; there are in fact docs on specific games which were reverse-engineered. It's less common, but it does exist. Sometimes romhacks a...

Three: said Wiki page contains a section called "Registers" which has a very well-written 2-paragraph description of the behaviour at the very top. The description uses both words and code, and is excellent at describing how the MMC1 behaves (that its registers are single-bit due to simpl...

So I've been using the Mesen debugger some code I found on github that is using MMC1, so I've been looking through some docs for the mappers. When switching levels, the code is writing to $E000 with 5 sta calls and lsr calls in between. Have you read the nesdev's wiki on MMC1? https://wiki.nesdev.c...

My point is don't include the three upper dots , they're confusing because nothing about the MMC1 has eight bits. Anyway: Battagline, you already asked, and tepples already replied, CNROM is supported . My mistake. I had forgotten CNROM was in that list. It doesn't really change that I would like t...