SpritesMind.Net

IC1 is a 7805 or similar: a 5volt regulator, I'm sure of it... Could well be. I wouldn't have a clue from looking at it. I've only listed part names where I'm sure about them though. Perhaps if someone manages to dump a retail Pico cartridge we can get more answers. I've got a couple of carts on th...

Out of curiosity, where did you get that file? Do we have a full blown official MegaCD SDK kicking around? (I've never really looked)

What do you think 315-5639(?) is, then? That looks like the bus arbiter. It'll also be in charge of the I/O registers at 0x80000X and the SEGA protection device if it's anything like the 315-5364 in the Mega Drive. Here's my list of all the chips, as best as I can figure. IC numbers listed as they ...

I've got a query about one thing notaz. How sure are you about the following info: The 68000 uses following hardware interrupt autovectors: level 2 - seems to be available, but most games put empty handlers here. level 3 - PCM interrupt? Probably occurs when PCM hardware needs more data, and exact c...

I think you'll find the PCM chip is the Sega branded 315-5641. It takes all 16 data lines (which according to the memory map the PCM chip does), and it's the only device on that board I can't identify.

I wasn't aware of the specs for the MSX; I've never looked into it. Well, reading the thread on the MSX forum, it looks like they had the same problem initially. The initial implementation took 447 T-cycles for each sample, giving a max of around 8KHz playback. Obviously they managed to improve on t...

Wow, that sample is impressive. I wonder if the Z80 in the Mega Drive would be fast enough to make the changes at the required rate though. At 44.1kHz, the Z80 would only have around 27 cycles to update each channel. That's 27 cycles to load the next sample data from the source, and write it to the ...

Christuserloeser wrote:

Nemesis wrote:And as a sidenote, it seems the URL tag doesn't work, and we can't use HTML in posts, so I can't see any way to create a link to a URL that has a space in the path.

You could use %20 for spaces. I can't remember what works with brackets though.

Thanks, I didn't think of that.

Oh, you're the guy who did the transcriptions. Kudos for that man. That must have been a hell of a lot of work. Personally, I find I tend to prefer to read from the original scans, but there's one thing the transcriptions are invaluble for, and that's ctrl+f. I've considered doing a new transcriptio...

Yeah, I've got the transcription. Still, it's nice to have the reassurance of the original scans to refer to. In that many pages, there has to be at least one typo.

As of this exact moment they're uploading, but the following links will work in a couple of hours: http://nemesis.hacking-cult.org/MegaDrive/Documentation/Sega_Genesis_Manual.zip http://nemesis.hacking-cult.org/MegaDrive/Documentation/Sega_CD_Manual.zip http://nemesis.hacking-cult.org/MegaDrive/Docu...

[here's how I once retrieved the correct value, your formula is not correct as it has nothing to do with 50hz/60hz: one line is approx. 63.69 us hdisplay is 63.69*256/342 = 47.67 us (same for both modes) this gives you : H32 (worst case is 8 words for VRAM) : 47.67/8 = 5.96 us H40 (worst case is 10...

About the FIFO, the documentation give the max number of permitted CPU access to V-RAM by line (btw, data rate is likely the dma rate) , as well as the max waiting time for the FIFO to execute one command, did you figured the exact slot timesharing between VDP & CPU ? Can we consider taht a VRAM wr...

Writing to CRAM during frame will cause some colored dots appear... I have no idea what happens when other things are written to. Oh, just to confirm, after thorough testing, the only kind of access to the VDP which causes these kind of glitches that I've observed are writes to CRAM. Registers, VRA...

Actually, the dots that appear are the colour of the value you write. Essentially, when you write to CRAM, the single pixel that is being drawn at that moment displays the colour you were writing to the CRAM at that moment, regardless of the colour that should have been displayed. This occurs even w...