SpritesMind.Net

Ok, so there is a logical hardware reason for this kind of distortion, it's not just some mysterious interference. In that case, I might have a crack at emulating it, or at least approximating the effect. I can see what you mean by the equal area above and below 0. The behaviour is easy enough to un...

Here's a "perfect" synthetic output from my emulator with no leakage decay:
http://nemesis.hacking-cult.org/MegaDri ... ukebox.rar

It'll be easier to compare. Won't sound as good though.

Yeah sorry, that was probably the wrong waveform to upload. The second one is being generated by my emulator, but I'm experimenting with leakage decay as described by Maxim in SN76489.txt. Obviously my decay is far too extreme in that sample. I've got to run some more tests on the hardware in order ...

Yes. I soldered a pin to the board partway along a track leading directly from the PSG output on the VDP, and sampled from that. So it's not "straight from the chip", but only a few cm further down circuit, and before any other components. Here's what I got when recording from "Jum's Genny PSG Jukeb...

Hah, here's something I didn't know about the envelope generator:

*The shape of waves of the envelope changes in exponential when
attacking it, and it changes in the straight line at other rates.

Does anyone emulate this correctly?

Well, there's a section in this manual about CSM on page 36. Here's what OCR + web-based Japanese to English translator has to say: 2-8-4 Setting of mode of CH3 Channel 3 can set the mode by $27 “D7,D6". Table 2-1C CH3 mode ------------------------------------------------------------------------ |D7...

yes, but doesn't every chip differ in term of frequencies value, internal conversion tables, etc... I think I've seen the YM2413 and YM2149 programmer manuals somewhere with lot of value tables but they can not be used for the YM2612 for example That's the reason this manual is so significant: The ...

There's quite a bit of stuff in there which isn't covered in the Sega documentation, like self-feedback, conversion to real frequencies, the actual way sounds are generated and operators are combined, etc. And of course there's lots of misc stuff like SSG-EG and the test register which aren't includ...

One interesting thing to note about this document is the numbering of the operators. In the Genesis document, we know they've got operators 2 and 3 switched somewhere, either in the register map or in the operator connection charts. Generally, we switch operators 2 and 3 in the connection charts to ...

A note about that "ladder" effect, I've seen a similar distortion when sampling the PSG output from the MD1, even when taken straight from the chip.

As anyone who's tried to emulate it will know, there's a significant lack of solid information on the YM2612. The only official reference we have comes from 14 pages in the Genesis Sound Software Manual ( http://nemesis.hacking-cult.org/MegaDrive/Documentation/GenesisSoftwareManual.pdf ), and they'r...

Ok, here are the first two Pico cartridge dumps to be released in the public domain: http://nemesis.hacking-cult.org/Pico/Mickey%27s%20Blast%20into%20the%20Past%20%28U%29.zip http://nemesis.hacking-cult.org/Pico/Sonic%20The%20Hedgehog%27s%20Gameworld%20%28U%29.zip I'll be dumping a larger batch of P...

From what I understand, there's only one parallel PCMCIA card for a laptop. It's very expensive, and it's pretty pointless to get one, seeing as PCMCIA is itself being phased out by ExpressCard. Most new laptops no longer support PCMCIA.

Alrighty, the Pico unit arrived in the mail this afternoon. It's taken all evening, but I've got a "working" adapter, and I've dumped a few roms. I say "working" because it's not really working yet. I've got a bad joint or a stray bit of solder somewhere or something, because I'm getting a little bi...

Some Pico carts arrived in the mail yesterday. I was hoping to dump them by cannibalizing a PCI connector and using one side of it to connect to the cart (49 pins per side, compared to 50 on the Pico cart), but the pin spacing is off by a fraction of a millimeter. I'm probably going to have to buy a...