nesdev.org

https://www.ecoligames.com/svn/FariaEditor/FariaLib/OverWorld.cpp Faria uses RLE, but with three different types of runs: 1) The three most common runs of metatiles (water, grass, forest) can have runs of 2 to 17 metatiles. Bit pattern is 0x11mmcccc (m = metatile index into lookup array and c = coun...

It seems to me that algorithm makes several assumptions that are not necessarily true for all games. A year ago or so I started work on a "static code analysis" project for NES games. The goal was to determine code from data by tracing all possible execution paths. For example, the utility...

If you see something like this: lda ($422),y sta $2007 iny lda ($422),y sta $2007 iny You've most likely encountered code. And most banks that are filled with data don't have lots of code in them. If you find the Reset routine, you can basically act as a 6502 chip and find out how everything works....

And if you need a basic example of a makefile for an NROM game, look at the makefile for Tetramino . I just looked at your project. I have a few questions, if you don't mind: 1) In your "nes.ini" file (ld65 linker control file), your "ROM" begins at $c000 but has a size of $8000...

tepples wrote:Reserving $0000-$000F for scratch space is more like those old architectures that store their registers in RAM.

Ah yes, like the Intel 8051. I had forgotten. http://www.howtofriends.com/8051/, section 2.5

I have not changed my game rendering code yet, but I have decided upon a map compression scheme. As with everything else, it is subject to change at any time. I'm still writing the 'C' utility that will convert PNG files into compressed map data. Documentation on the map format are here [1] and the ...

I was looking over the source a few days ago and noticed you documented which registers were destroyed. Wouldn't it be better to document which were preserved, since it's better to assume destruction than preservation of anything unmentioned? 6 of one, 1/2 dozen of the other I guess. Maybe. Since t...

Exactly halfway into the file (physical offset $4000) it would have the string "bye cruel world" OR "cruel worldbye " (more on this later), followed by more zeros. This is the part that I thought could happen: depending of the order you link the files, the content could be in a ...

I have a question regarding your code. I'm a newbie too so don't be too hard on me :) I checked your files and you seems to re-use the same segment in many files. What is the advantage of this? My first impression was that 1 segment is declared once and that's it (impression only, cannot find any d...

Hello Everyone, A few people have asked to see my source code. Please consider this disclaimer: 0) If my code helps anyone I'd like to know. Since I'm just starting out, I fail to see how it would be useful to anyone though... 1) I'm not an expert NES developer - I'm a newbie. Please don't assume th...

I have three NES related projects in my subversion repository open for browsing. I'm trying to install "trac" so that you can get the full benefit of a web interface into subversion. I'll post URLs once I unscrew it.

Thank you for the testing on real hardware! I have considered sharing code. I don't mind sharing the "engine", but I kinda want the game content itself (story, art work, text, etc...) to be 'secret' for a while (that stuff isn't even coded yet). I will share this though: much of my "d...

Ok, I've got the status bar working using sprite-0 hit detection. Thanks for your help guys and gals. The playfield doesn't scroll yet, and I've made not attempt to hide "sprite-0". (plus I only have three meta-tiles defined, so the map looks very rough). Anyway, feedback would be apprecia...

I know that I'll get garbage; I'll live with it for now. Crystalis in MMC3 and uses IRQs to handle flipping name tables and some really funky code to splice the two name tables together on the fly. I'm trying to stay with MMC1 (for now) in case I want to fab a cart or two. We can purchase blank MMC1...

I never understood what "single screen mirroring" meant, but by what you just said that sounds like what I need. It should be fairly easy to test. Thanks!

[back from testing]

Yes, that looks like my solution. Thank you very much Dwedit.