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I took a look at the timing logic and I realized that the counter that keeps track of the shift register position actually only resets every 18 cycles instead of 9 cycles like I originally thought. The timing sequence itself is 18 cycles long. The shift register is writable only on the first 9 cycle...

Ben Boldt wrote: ↑

Thu Feb 18, 2021 2:48 pm

Do you see any possible detection of register $9008 on the VRC7 die?

I have checked the address decoder already, but I might need some elaboration on what you mean.

The official YM2413 datasheet claims 84 master clock cycles. Since the VRC7 runs at twice the 2A03 CPU clock ... 42. Oh? I have only seen a datasheet of YM2413 where the only thing given in cycles is the reset pulse width. Do you know where to find this datasheet that list this info? Also, accordin...

I recently got back to inspecting the die shot of VRC7 and I found out few things that might be relevant to emulating the chip (or just in general interesting observations). I don't think any of these are mentioned on the wiki page either (or anywhere else as far as I have read). While VRC7's master...

I'm not sure if there are mappers that can map CHR-RAM to ROM area, but I was wondering if there is a way to mix two DMC samples in software an put the result in CHR-RAM in area where the DMC channel can play it? If there is a way, I don't think simply adding the samples together would work, which i...

I don't remember mesen having a disassembly feature (unless it was added just recently). I don't mean disassembly as in begin able to see the code in the debugger. I mean it as in disassembling the code into text files (and maybe chr and dmc files too).

If one doesn't exist yet, I was thinkin of making one. Basically you play the game and it logs stuff and when you are ready you can disassemble the ROM. Some basic features that are needed probably are: Code/data logger Address/lable logger Branch logger Basic debugger Hex editor The branch logger c...

The wiki also mentio s that the expansion RAM can only be written while PPU is rendering. Is this right? And does this mean rendering as in rendering begin enabled from PPU registers or while a frame is begin rendered?

According to the wiki MMC5 has the PRG RAM at $6000-$7FFF. When you are using the extended RAM modes 0 or 1, what parts of the PRG RAM are used for these features? Mode 1 can also be used as a extended nametable. How does this work with the additional attribute data used in that mode? The wiki menti...

A low-pass isn't necessary unless the original sound has a lot of higher frequencies you don't want. Converting the sample usually does have a low-pass like effect on louder frequencies, but it might not completely filter them out. Although due to the bit crushing that happens you will still get som...

I was curious if anyone here know how you should prepare a wav file to be converted as a DMC sample to get the best result. One trick that I know for percussion samples is that you add some white noise the sample and it'll hide the "crackling" sound you get at low volumes. Are there any recommendati...

The NSF for Hebereke (and probably Ufouria too) has two versions of the title screen theme. One with the triangle channel and one without. I was wondering if both exist in the ROM as separate tracks or if the other was added to the NSF manually.

I think I have a good idea on how the solid collision should be made. Not sure if it was mentioned here, but I heard of technique where you compare how much the hitboxes overlap on X and Y axis and push out the axis that has least overlap. If they are equal you could implement special cases on which...

How do you then detect from which side the player "penetrates" the solid object? Do you need a special case if the player penetrates the object exactly from a corner?

Here are few examples: 1. Player jumps while moving left/right and hits the bottom of solid object. You would need to push the player down here. But if you push player on X axis first the player would zip to the side of the solid object. 2. Similar case if player falls while moving left/right and hi...