nesdev.org

And by the ppu 'not rendering', you mean not writing lines 0-239 of the visible frame, right? "Not rendering" is either VBlank or forced blanking (SPR and BKG off). Also, does the 'data' that is written to 2005/2006 actually get written to the memory location 2005/2006 all the time as wel...

You should always let $2005/$2006 writes affect 't' and 'v', no matter what the PPU is doing. If you emulate correctly the way the PPU makes use of 'v' while rendering, scroll changes should work without problems in case the PPU is rendering. If the PPU is not rendering, 'v' will be used by the gam...

I have read many times in several places about how VRAM can only be read/written during VBlank. I am still a little confused about this. My question is, when do I use data written to 2005/2006 for scrolling and when do I just write to 2005/2006 and ignore the data as scroll data? I know that sometim...

Marat made iNES. I don't know who made Pasofami, which took split ROMs, and even the Google translation of the site that zophar.net links to as Pasofami's official site doesn't clarify things. I once had an IBM PS/ValuePoint with a 25 MHz 486SX CPU. Even Nesticle for DOS didn't run at full speed on...

I was wondering what hardware they might have had to work with. I found a nice resource on Tom's Hardware: http://www.tomshardware.com/reviews/mot ... ,1175.html

I'm just wondering if anyone knows any details about the earliest NES emulator to be released and what hardware it was running on. EDIT: I should say that the real reason I'm asking is because I'm wondering what the slowest hardware is that you could run a NES emu on. I know that's up for debate sin...

I have already switched my code over to per-pixel rendering. It was a little more of a pain than I expected, but it seems to be working well now. After working on this for a bit, the benefits are quite clear.

It would be recommended to atleast do per scanline. The state of things at the end of rendering which is likely when you draw the frame now is not enough to fully emulate the PPU. Graphics banks can change, scrolling and nametable registers change, etc. The easiest for coding point of view is to em...

Right now I have VERY basic timing code implemented. And I am rendering on a per frame basis. I was wondering if I am going to run into unforeseen trouble down the road using this method. I have gotten to the point where a few games are working, but I don't want to do a lot of heavy ppu coding and r...

Those bits indicate the name table where rendering starts . Due to scrolling and screen layout/mirroring, different name tables may be visible at different parts of the screen. Galaga appears to use "negative" scrolling, meaning that although rendering starts on the name table indicated v...

Some games switch nametables during the game (like going from a menu to the gameplay). How do you know which nametable to use? I have been checking bits 1-0 of 0x2000, but that doesn't seem to work properly. For instance, when Galaga starts, it is using $2800 and is mirrored at $2C00, but when the g...

In 8x16 pixel mode: OAM tile number $14 -> $0140 and $0150 OAM tile number $15 -> $1140 and $1150 OAM tile number $16 -> $0160 and $0170 OAM tile number $17 -> $1160 and $1170 It's convenient that the base of the hexadecimal number system commonly used for VRAM addresses is the same as the length o...

If anyone happens to have a better more accurate nestest.nes log that is as easy to read as the current one used for comparison I will gladly overwrite the current one. http://nickmass.com/images/nestest.log is just some log I found in a post on these forums made ages ago that I happened to use whe...

No, I said how to find the pair , i.e. the top tile. The bottom tile is the one immediately following it. So if the top tile was number 20 in the OAM (out of 64), then the bottom tile would be 21? And its address would likely point to the same address in the pattern table with the offset of $1000?

If there is bit to indicate whether or not the tile is located at $0000 or $1000, why do reference documents say that one tile is always at $0000 and it's associated lower tile is always at $1000? If that's always true, what's the purpose of the bit? ...with bit 0 of the second OAM byte selecting t...