Recent content by Rivet

I've been wondering this for a while. Other than the usual clearing memory, initializing joypads, PSG, and setting VDP registers, what other things would I have to worry about when starting up the console? One I did hear about recently was other factors like making sure there isn't a pending DMA...

I've been told that there's many things (like jump tables pointing to some general routines, I've heard that Nemesis compression would be one) in the Sega CD's BIOS that is carried across revisions that could be used when creating your own programs. Is there any good reference for what can be used?

Wonder why it would include former data? I suppose you could always just write once but read two or three times in case. Either that or do some NOPs like you said.

I know that chuck rock 2 uses the ASIC during gameplay and it seems to maintain 60 fps. I just wonder how much you could push it and still keep 60. (I'm curious what's going on with the image, though. It's a little broken on emulators for some reason)

Must have been someone else or something. Not completely sure. Is the ASIC generally quick when generating an image? Or can it take up to a frame or so?

It might've been you who recommended that I did that, Devon, but I could be forgetting what exactly you were talking about. You probably were just recommending I wait in a loop while waiting for the other CPU to respond. I was mainly asking this to see if it would be feasible to send large...

I'm curious. How reliable are the communication registers between the Genesis and the Sega CD? I've had it recommended to me to make sure that something I've written to them was sent and the other CPU recieved it. Would this be due to the CPU speed difference or just the hardware being finicky?

They should still operate. Have you not heard back? Maybe try a followup email?

Way back in March, a discord user by the name of PinoBatch was making programs on various consoles that displayed the Ukrainian Flag by setting the top half of the screen blue and the bottom half yellow. I noticed that he hadn't made a Genesis version yet, so I figured it could be a neat...

From the looks of it, it seems you ended up with some development versions of games! These are usually things that you want to back up so they aren't lost to the tides of time. If you're interested in preserving them, the folks at Hidden Palace might be able to help you out. Very neat find as...

Here's a test I did for something I'm working on, a normal Genesis sprite but I can control it's X position every line. It's w.i.p and has no graphics yet. Bizhawk doesn't emulate it correctly for some reason, so the first line is static.

Since there's been a rise in interest in Sega's mushroom (More interest than the CD currently) I figured it warranted a thread! Some things to start off: XProger's W.I.P OpenLara port: GenesisFan64's Marsiano project: Victor Luchitz's various projects: And finally pw_32x's currently...

I noticed that the sound test has 2 DACs listed, does this sound driver use DualPCM?

Recently, PinoBatch made some small ROMs for the NES and SNES that changes the top half of the screen to blue and the bottom half to yellow. I wanted to give this a shot to see if I could go any lower. With the help of Jorge and Tails8521 we were able to squeeze the ROM down to an impressive 128...

I discovered some possible mistakes when going over the Software and Hardware manuals of the Sega CD. The Software manual seems to indicate that the Sub-CPU shouldn't be able to write to the Comm or Status registers... But the Hardware manual seems to say otherwise! I don't know if what was...