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I've recently found that passing arguments can prove to be somewhat troublesome depending on what you have in mind. Obviously, one might go for a route where each CPU register holds one of the arguments assuming there are up to 3 arguments. Some situations might call for a method that only uses 'A' ...

Sometimes I wonder if anyone else feels like that when finding a solution to a certain problem during development (be it NES or otherwise). Like this instance where I had a bunch of things to comment out, but no "block comments" in ASM6: .if 1 = 0 .db 0,3,6,9,12,16,19,22 .db 25,28,31,34,37,40,43,46 ...

14 914 CPU cycles 14 914 APU cycles. I did mean CPU cycles. Since the write immediately decrements the length counter of the channel in question, only 2 frame counter steps out of the 5 have to occur before the length counter gets clocked again, which amounts to 7456.5 APU cycles. I'm not exactly s...

Here's an idea that may or may not be useful, but I thought it would be worth sharing here. So the frame counter allows for clocking the length counters at a ~96Hz rate with the 5-step mode selected, and writing to $4017 clocks all the hardware timer units. By writing $18 to $400F and then $C0 to $4...

The effect of BIT is probably why I use it the most. The way I handle the math doesn't really need the V flag because most of the time I add signed 16-bit values to unsigned 16-bit values... so I still only ever need the carry for that (though I have to interpret the carry differently based on the s...

I've always tried to address this from both directions: My engines can either have a length counter-like timer in software to stop the sound, or a "stop the sound when less than X frames of duration are left for this note". It makes things as opened up as I need them to be.

In a game (provided that the sampling rate is not too high), any N163 channel could be easily used to play 4-bit PCM data with volume control by having the channel set to a 4-step wavetable, with all steps of that wavetable always being equal. To avoid potential noise coming from the little time del...

I've had this crazy idea of "could an NES game cartridge be removable without the game crashing?". I realize the space issue would be huge, since there would only be a bit above 1.5k of code that could be housed by the RAM, while still leaving some zero page and stack space for variables. But the bi...

Great job, especially because now we can listen to the samples without any NMI or OAM DMA cutting into the sound like in-game.

If you want easy wiring the SN76489 could also be useful, you only need one register for it (some bits of the data written determine which channel receives the lower bits and whether it's a volume or period register write)

I was inspired by the "A Mind is Born" 256-byte demo on the C64 to try and put something interesting in the same amount of space for the NES. Not counting the stupid required system init things it does fit into 256 bytes and there's a TON of ways to improve on this but this was just a proof of conce...

There is a practical use if you want phasing effects to behave differently. For example playing the same note, but with slightly offset pitch on two channels using 25% and 75% pulse-width results in a high-pass filter-sort of PWM effect instead of the usual phasing (it's recommended to retrigger the...

I'm slowly getting into creating some of the assets for my game (8k CHR-ROM only) and I'd like to get some criticism and ideas on how to improve myself. Generally I practice with art I receive/commission or find on the internet by using them as a base for "pixelization" as far as the mugshot and the...

Two things that stood out to me:
- $2007 is the PPU_DATA register, your table makes it look like it is part of the mirorred address space.
- The iNES header is 16 bytes, not 256 (but the rest of the tutorial with the ROM addresses actually considers it 16 bytes).

For one of my stages in my game with lava at the bottom, I'd like to create a sine wave movement pattern to make things look more interesting. However, my game is small and is based on very simple cart hardware so I use the DMC for raster effects. I know that I need to do this with timed code becaus...