nesdev.org

3_5MHz Pierce Osc.png OK so here is a simple Pierce Osc @3.579545. My Xtal is 3579.454KHz I used 4.7M instead of 1M @ R1 1.8K instead 2.2K @R2 C1=C2=22pf and a 74hct14 One could delete the second inverter gate butit's nice as a buffer. There is a ton of examples on the net but this was a help with ...

Thanks, this does help out. well I've been searching and have some links for OPL2 designs also. A DIY Adlib card http://www.malinov.com/Home/sergeys-projects/isa-opl2-card A midi synth http://kikyoya.files.wordpress.com/2013/10/fm3812sch.png?w=465&h=303 The C64 Sound Expander http://kikyoya.fil...

@infiniteneslives Don't know if you need any of this? Here is an Arduino shield w/YM2413 that may assist with the output mixing http://htlab.net/products/electronics/ym2413-shield-1/ and http://htlab.net/wp-content/uploads/2012/12/YM2413_Shield_Ver_1.0.pdf Looks like a basic opamp mixer. Using a qua...

You fell for the MHz myth. The 6502 does much more in each cycle than an 8088 does; I direct you to any Spectrum vs. C64 flame war. On how many of those cycles is the PC actually transferring data? :) I guess a lot of my concerns stem from my background with the Atari 800. 6502 processing is effect...

@ Ladnariq Glad we're 'Good'. My main direction with the YM2413 was motivated by the similarity with VRC7 and the fact that INL had interest in a VRC repo board. Fitting a CPLD with the FM core is a task and in a hope to see a FM cart, this chip seemed the closest fit to the direction INL was going....

I appreciate the discussion on this subject everyone. I don't consider it off topic in the slightest since I had actually already had thoughts of incorporating a FM synth on this board. I can't say it's the highest priority on my project list, but it is indeed something I'd like to do with this des...

ROMs using just the 2A03 PSG already have to store duty, volume, and pitch envelope data for instruments. A table of FM parameters for a 2-op FM chip wouldn't be that much bigger. Well from: "Programming the AdLib/Sound Blaster" http://bochs.sourceforge.net/techspec/adlib_sb.txt The sound...

These are the same currents within the Atari 8bit community, so I can appreciate the resistance to innovation. But I truly feel that the OPLL isn't too strange from a HW point. If no one else ever does this hack that is fine with me. It's not even resistance to innovation. It's that ideas are cheap...

never mind that there are no 'new' synth/tone chips, just DACs and DSP With DSP synths, there's still a problem of how wide to make the interface. A pure sampler like the Super NES DSP produces static, muffled sounds compared to an actual synth that provides variable-controlled filters, but if a sy...

The thing is, once you start adding novel hardware—and yes, the YM2143 counts as novel hardware, even though it's similar to the VRC7—there's no reason to constrain what you add at all. Maybe it's a VRC7 clone ... that only outputs 50% duty square waves. Or maybe it's a VRC7 clone ... that actually...

Forever ago, I bought a sound blaster clone card that had implemented the OPL2 in an 8051 clocked at 12MHz (≈ 500KIpS) with an 8 bit R-2R-4R-&c resistor DAC. We should be able to reimplement the VRC7's synthesizer in a fast modern microcontroller just fine, especially given that the Lagrange Po...

VRC7 is a little problematic, since the VRC7 has a custom patch set that is not shared by the YM2413. You can put a YM2143 on an NES board, but it wouldn't be great for a Lagrange Point repro. All of the tunes will sound at least a little off, some a lot. It might be a fun board to play with, but y...

Nice! You caught my attention with NSF mapping and VRC support :) I've been on a OPLL tear last few days (week), dropped a little money on EBay for a few YM2413s (prob clones but were very cheap to mess around with) mainly for adding FM to GameGear. But also interested in VRC7 sound; which brings me...

Hi. Sounds like you jumped in with both feet! Well, you could re chip a SFROM board with slight re wiring for the PRG rom. You should be ok with the CHR rom if the hack uses 32K. If it uses a 64K image you will need to do some extra work, because the SFROM boards have a 28 pin footprint for the CHR ...

Just tried "d2" in the dump part of the line instead of "d", and it seemed to work. It loaded up in Nestopia and the the image info screen says the dump is "OK". I'm going to test a few more. Good to hear; Just about to post a reply about that pram :) Also in my folder...