SpritesMind.Net

Yeah, "trigger" refers to the letter buttons (several manuals and in a handful of cases the games themselves refer to "A trigger" / "B trigger" / "C trigger"). Contrast with Start button and Directional Pad. B maps to the Atari button because the Master System controller has two buttons and their in...

Edit - I'm putting together a new spreadsheet of Sonic mods changed by the IO fix, and I'm trying Griel's Quest again. It turns out that on the level select menu, for some bonkers reason buttons A and C are 'confirm' and B is 'back', which is outrageous! Uuuuuh, what else do you expect them to be? ...

If BlastEm barfs at a hack you can probably assume the issue is the hack :​P And yeah, games rely on telling apart between cold and warm boot not only because of the init skip stuff (not sure why Sega insisted on that ), but also because most games don't reset the options when you press the Reset bu...

Yeah, interrupts have to be disabled because that's what 68000 does on reboot (remember not all systems have TMSS so on those the game is the bootstrap). And yeah, the state of the I/O ports on boot is how games tell apart soft reset from hard reset. Also, Z80 should be left reset on boot as well (a...

Make sure to enable errors. For some reason asmx has error reporting disabled by default… (why is that even a setting?!)

Um, you're supposed to do word writes, not byte writes (incidentally, a color is word-sized). You can use longword too (which the VDP sees as two words). Byte writes are likely not doing what you expect. Also this should give you an idea: https://plutiedev.com/tiles-and-palettes#loading-palettes The...

You know how you have 32KB worth of SRAM, right? sRamOffSet is the location within SRAM.

sRamOffSet = 0x0000 would be the 1st byte, 0x0001 would be the 2nd byte, 0x0002 would be the 3rd byte, etc. (up to 0x7FFF, the last byte).

Not related to your question, but how did you manage to miss the Samurai Shodown character select? (especially in 2P) It takes palette swapping even further. Also yeah, timing is a big issue, even if you use asm honestly, because when the 68000 responds to the interrupt the VDP will be likely in a p...

You have to keep redrawing the tilemap as the camera scrolls (the tilemap can only hold a chunk of the image, you need to keep drawing in new chunks as it moves around).

EDIT: yes, this goes even for drawing blank tiles :​P

In favor of Accolade (even if eventually Sega decided to just give them a license after that anyway). And other countries tend to be more lenient (turns out most jurisdictions are not happy about actively blocking your competition, especially European ones). I'd say that the misleading TMSS message ...

Only $100-$103 are checked. That said, not respecting the ROM header is frowned upon so don't do that. Especially since emulators will sometimes rely on the ROM header to detect some stuff (e.g. how much SRAM is installed, or which region to set as default, some may also automatically switch to peri...

OK this stalled again I guess. I'm still not sure how to describe /CAS2 and /ASEL. I know they're related to DRAM refresh, and that /CAS0 asserts before /CAS2 when it happens, but that's it. I'm not sure under what circumstances this refresh cycle is asserted though. Is it regularly? How often? What...

Well, you could attempt to add up sine waves (so size still tied to length, but still much smaller than full blown PCM)… but even if it was reduced to a single sound (e.g. speech) I'm not sure how far you can get with just a few sine waves (unless you want to start eating multiple FM channels). I re...

That's the expansion port rather than the cartridge slot. Does that make a difference? I don't think so, many of the signals are shared between the two (and some of the Mega Drive components too), e.g. /CAS0 acts as the output enable for everything that isn't work RAM (for some reason work RAM gets...

Black starts at 25mV above ground and goes up to 800mV with more or less exactly 25mV steps on red and green channels, but blue channel is about 20mV lower in full scale amplitude, which explains the subtle yellow tint compared to MD output that is seen on all 32X I have had access to. 3 2 X Anyway...