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So I'm trying to create an asteroid out of background tiles and I'm running into issues where garbage is showing up in my background under certain conditions. If I write 4 or 5 tiles to the background everything is fine. I am trying to copy over 4 entire rows of tiles starting with the top left corn...

Anyway, if I can't change the mirroring I can just have the largest asteroids move horizontally only. Kinda boring, but this is just a learning project so it's not the end of the world. Thanks. If you asteroid is smaller than the screen, you can still scroll vertically and dynamically load/unload r...

If you just want fixed 1-screen mirroring, you could target MMC1, ANROM, or mapper 28. I'm not going to use a mapper for this game. I'm just trying to get something done and trying to keep it as simple as possible. I want to figure out Mappers soon, but I'd like to get this game finished up this we...

Only with some mapper. FDS might pedantically count as close enough to NROM, with mirroring control, for your purposes. Maybe. I was going to make the largest asteroids in my asteroids clone background tiles. They would all have to more in the same direction, but if I had it set up to mirror in all...

Can an NROM cart change it's mirroring on the fly? Or can that only be done with a mapper?

Thanks

dougeff wrote:Are you sure PPU control $2000 is set to +1 mode and not +32 mode?

xxxx x0xx

This bit should be zero.

Actually you were right. I was setting $2000 to #%10011100 earlier than I thought I was.

Thanks!

dougeff wrote:Are you sure PPU control $2000 is set to +1 mode and not +32 mode?

xxxx x0xx

This bit should be zero.

It was set to 0 because I'm writing to PPU Address $2000. Is that not right?

Thanks

When I was looking through rainwarrior's ca65 template, setting up the nametable seemed pretty straight forward. He was using the x and y register and looping 960 times doing a STA on $2007. I was able to play around with that code and thought I understood it. But when I'm trying that in the game I'...

pubby wrote:Enable the BG bit in your writes to PPUMASK ($2001).

Well that was easy

Thanks!

I've tried this in both Mesen and FCEUX.

If I open up the nametable viewer in either of those emulators, it's filled in with the default background tile (a starfield). The actual background in the game is appearing as plain black for some reason.

Any suggestions?

Thanks

pubby wrote: You can't allocate variables in ROM.

*forehead slap*
I keep forgetting about the hardware details.

Thanks

One mistake I made was to give a temp variable a pseudonym (like local_X = temp3). I thought it would make it clearer about what the temp variable was doing. But then I used another function which clobbered the same variable, and I couldn't figure out the problem because of the alternate name for t...

pubby wrote:The foolproof way to never clobber registers is to use an actual programming language

ahh, but 6502 assembly is part of the charm of NES development

My idea is to mention in the comments what registers are being used, so that you can remember. In the case of macros, you can also require the registers to use as arguments to the macro. (I have done both of these things.) I've been doing the comment thing, but my problem is I don't always go back ...

Ok, so this may be a really stupid question, but I just spent several hours debugging some weird behavior in the game I'm working on just to realize the problem was I have a macro that was clobbering the value in my x register. My main question is what strategy do developers use to make sure they ar...