nesdev.org

In our game, I am currently going with a 12.4 fixed point number format for position and velocity. (I've been thinking of 16.8 for speed of fetching and better resolution but I figure I can save memory for now and upgrade it later) How would we do a fixed-point multiply on 6502? I figure the general...

I'm still not sure what you mean. No matter the sprite size, you loose 9 sprites out of 64, with 55 remaining which means you loose 14% of your sprites. Them being 8x8 or 8x16 doesn't affect this. On the other side you loose twice the area with 8x16 sprites because you're loosing sprites twice as b...

DMC playback causes glitches on the controller lines. There are workarounds for standard controllers and the Four Score adapter, but these may not be compatible with some specialty controllers. It can cause problems with the Zapper and the Super NES Mouse, for instance, unless you read them only wh...

The vblank code in Battletoads does indeed use tricky-as-hell cycle counting. But there are other substitutes for a scanline counter, such as abuse of DMC IRQ. When I read about the existence of the DMC IRQ this was my immediate thought - maybe it could be used to count scanlines. Does it actually ...

As no one seemed to mention it: Battletoads does keep rendering disabled for 20 or so (iirc) scanlines into the frame, showing that some commercial games did it at least (maybe lots of games did, but I only know of that one). This is what makes it tricky to emulate, as the current screen position n...

In case anyone cares, I've created a test ROM for TNROM or TGROM boards that have been retrofitted with 32KB of CHR-RAM and rerouted to allow all 32KBs to be bank-selected. This configuration is also possible with the development boards that Infinite NES Lives is planning to release soon, and I int...

Jeroen wrote:Did you just bump this just to tell him something people already told him? (That context is not a compiler/assembler)

Oops, erm.... yeah I guess it was a pointless post. I stumbled on the thread from a search.

There is a C compiler for 6502/NES and many of us here use it: http://www.cc65.org/ The words you are using still makes it hard to understand what your goal is. Please explain more about what you are trying to do. Be specific about it, not general/vague. What kind of C program do you have? Who wrot...

To save ROM space I may do a combination of tables and calculation. But if all tables / unrolled loops would take a mere 10% then maybe it won't be so necessary to get extra vblank. I just figure that having a smaller viewport for the playfield is a decent price to pay just to have a little more tec...

No, not changing the design of the game... just how the map is broken up. We have decided to create a top-down adventure. We are bouncing lots of ideas around at the moment so really it's going to be somewhat of a compromise between design and technical power. We are working hard on the R&D side...

It's NROM-256. Will it be too hard? If you are not scrolling vertically, not so much, because you can use sprite 0 hits. The simplest way to do it would be to set up a sprite 0 hit at the point where you want to turn rendering off. Once you do it, you are free to use the PPU as if VBlank had starte...

It's NROM-256. Will it be too hard? :/ I'm prepared to do some trickery. Just nothing that prohibits doing other things... can you explain how you would do it? What are the disadvantages?

I was thinking, to get some extra VBLANK I can disable the PPU at line 200 or whereabouts and effectively start an early VBLANK, right? What if I also want to start the next frame late like at line 16 or 32? Is that possible? I'm going for a letterbox effect.

Here's a minor suggestion, you don't need to take it... In Super Mario 1, if Luigi gets a fire flower, he is indistinguishable from firey Mario. I always thought that was annoying to no end. So if you are going to change which palette a character is using, I would suggest that you make it blink bet...

I thought I should mention that I've settled on a hybrid NMI approach - vram updates and music in the VMI, with a "callback" in the NMI to do whatever custom stuff needs doing, and controller polling and game logic in the main thread. Trying to poll controllers in the NMI was a disaster, n...