Re: The way to detect OPL3 clone
Posted on 2017-09-11, 09:09
Thanks
Re: The way to detect OPL3 clone
Posted on 2017-08-31, 01:31
OPN2 has this bug too.(YMF276 variant at least) Here's my test code: for(int i = 0; i < 0x200; i++) { writereg(i,0); } writereg(0x34,0x03); writereg(0x3c,0x01); writereg(0x44,0x0f); writereg(0x4c,0x06); writereg(0x5c,0x02); writereg(0x64,0x00); writereg(0x6c,0x00); writereg(0x74,0x00); writereg(0x7c …
Re: The way to detect OPL3 clone
Posted on 2017-08-27, 15:49
Thanks again 😀 It's interesting that OPL2 has this bug. I wonder does any other Yamaha FM chip family has this bug.
Re: The way to detect OPL3 clone
Posted on 2017-08-25, 11:59
Thanks!
Re: The way to detect OPL3 clone
Posted on 2017-08-03, 18:01
Kamerat wrote: Here's the ALS4000 PCI sound card, the FM synth should be the same as the ALS120. Sounds legit. Edit: Also added the FM801-AU, doesn't come close to the real deal... Added, thanks.
Re: The way to detect OPL3 clone
Posted on 2017-08-03, 13:00
Stretch wrote: nukeykt, ESS Solo-1 has hardware FM synthesis. Here's a screenshot of the FM port settings in device manager. How accurate it is? Or it is just ESFM?
Re: The way to detect OPL3 clone
Posted on 2017-08-03, 06:24
I cannot hear a difference between the 3 sound cards I recorded from. I ran the program under Windows 98 SE command.com Interesting results. YMF744 has real OPL3 so no question here. CMI8738 is believed to have real OPL3 and this recording confirm it. But ESS1938 is surprising. Perhaps they were …
Re: Windows, Doom, Apogee OPL3 Synthesizer.
Posted on 2017-08-02, 12:10
Will nuked opl3 2.0 be compatible with the drivers in there current form? When you release 2.0, I plan to recompile my version of the drivers with the new core by replacing opl3.cpp and opl3.h with the updated versions. Will I have to make any other changes so it will compile, or do I just replace …
Re: Nuked OPL3 Patch for DOSBox(+Windows build)
Posted on 2017-08-01, 15:29
James-F wrote: Hi nukeykt. Will NukedOPL v2.0 be available as a patch? Yes. When i'll finish it.
Re: The way to detect OPL3 clone
Posted on 2017-07-29, 09:13
James-F wrote: Does that mean you can improve NukedOPL to be exactly like the hardware? Yes, it is already fixed in upcoming NukedOPL3 v2.0.
The way to detect OPL3 clone
Posted on 2017-07-29, 08:29
Today i wrote program that can help to detect OPL3 clone. This program plays simple 440hz sound. It sounds like simple sine wave on OPL3 and like FM sound on clones. This program relies on hardware bug that presents in the real OPL3 core. I've tested it on YMF718 and various emulators. Report your …
Re: Roland SCC-1 - MIDI garbled?
Posted on 2017-07-25, 15:47
I'm think there are some damage in traces between PCM chip and sample ROMs. One day i tried to desolder ROM chip from SC-55mkII to dump it. And I broke some chip legs and traces on PCB. It sounded similar to attatched sample. Fortunately i've fixed it.
Re: YMF262 design flaw
Posted on 2017-07-14, 22:28
That is very exciting info, I am so amazed/stunned by this. I'll definitely try these after I've tested the attack rate thing. I've been thinking if this is the correct way to test it: -initialize all registers so chip produces dead flat zero value silence -configure one channel so that only one …
Re: YMF262 design flaw
Posted on 2017-07-14, 16:52
Figured out some of the LSI test(0x01) register functions. Note that i haven't tested them on hardware. This list can be incomplete or incorrect. bank 0 0 - Disable EG output 1 - Disable LFO timer(possibly also timer) / Set Noise generator's next bit value to 1 2 - Reset phase generator counter 3 - …
Re: YMF262 design flaw
Posted on 2017-07-13, 13:36
Hi nukeykt. Is this a significant bug fix that can be heard on most games like your samples above? The technical stuff is way over my knowledge, is there a significant difference? I think this bug never appears in any game. To trig it should change attack rate to 15 after keyon. I don't know any …
Re: YMF262 design flaw
Posted on 2017-07-13, 11:01
Finished work on envelope generator. Seems it works flawlessly 😀 Here's few records i did with DOSBox. highways.mp3 also demonstrates new rhythm mode emulation
Re: YMF262 design flaw
Posted on 2017-07-13, 01:24
Hi! Noticed Lord Nightmare mentioned me so I decided to make an account. You're doing good and fascinating work that complements my own/LN's! :). Might as well give an update while I'm here: I did a blog post as a tutorial about REing NMOS chips such as the YM2151 and friends back in October. A …
Re: YMF262 design flaw
Posted on 2017-07-13, 00:50
Wow, that's some pretty deep stuff you've been working on. So how come the MAME polynomial matches the output of real chip then? Is it just that the operator that was under examination used every N:th bit of the noise generator, so MAME polynomial matches every N:th bit of the original noisegen? I …
Re: YMF262 design flaw
Posted on 2017-07-12, 18:52
I'll put it on my todo list but I can't make any estimate when that will happen. Meanwhile, can you provide some information about this die shot reverse engineering, I'd be happy to read and maybe comment on something, although my experience is only limited to figuring out OPL2 KSL lookup table …
YMF262 design flaw
Posted on 2017-07-12, 17:53
Hi Recently i was working on next version of Nuked OPL3 emulator based on YMF262 die shot analysis. I think i found an error in chip design. YMF262 is specially treating attack rate 15: it just sets envelope to max value. Logic gates responding for this likely has an error. The logic looks like this …
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