What's your point? Why do you ask? Improve the current emulation to the world's best and accurate OPL emulation cores, almost to the level of real chips. Or if you think they are already so good that there is no room for improvement, please say now so I'll stop. For example, the following tables …

One more core YM3812, similar to YMF262 core values. adlib.cpp (again) #define OPL2_INTERNAL_FREQ 3579545 fmopl.cpp: OPL->freqbase = (OPL->rate) ? ((double)OPL->clock / 72.0) / OPL->rate : 0; Again, freqbase should be exactly 1 when integer mixingrate is 49716. Thus OPL2_INTERNAL_FREQ should be 72* …

Sorry for the trouble splitting the thread, thanks so it has better visibility. More cores, eh? Let's see! opl.h: #define INTFREQU ((fltype)(14318180.0 / 288.0)) // clocking of the chip opl.cpp: generator_add = (Bit32u)(INTFREQU*FIXEDPT/int_samplerate); So Ken Silverman's emulation core is best when …

Yes, too sceptical :) Well I took a peek at the code. First to make all increments 1, the float variable chip->freqbase needs to be initialized to 1.0 exactly. As this is calculated from chip->clock (oscillator speed used to clock the OPL3) and chip->rate (mixing rate samples are taken from output), …

DOSBox 0.73 added the ability to run its OPL emulators and master mixer at 49716Hz. I have to check the emulator code, but running the emulator and mixer at 49716Hz still does not mean the samples are generated 1:1. In some emulator code, I have seen the internal reference rate been set to 49720 or …

Frankly I'm a bit surprised that in 2009 we still haven't found the Valhalla of emulation yet. The digital end is pretty straight-forward and emulating an AdLib one would think would be quite possible. So I guess my question is, is it that the emulation is that difficult or is it that not enough …

That clone is similar to one that was reverse-engineered by someone else (Grischenko Alexander, Latvija). The reverse-engineered schematic (digital parts only) had Soviet clone markings, those with K555xx something, instead of 74LSxx. Otherwise it does exactly the same thing, but the 14.318MHz bus …

Yes sometimes a digital inverter can be used for analog signals too. Good news is that I was able to figure out the connections of the digital parts (bus address decoding, buffering, clock divider, etc) and the connections match my expectations. Chip select decoded from address bus with the two 138s …

As said, no program, just standard logic chips. So far I have gotten this far with the info - had no time to analyze the new pictures yet. The 74LS109 is a dual JK-flip-flop which is used to divide the 14.318MHz ISA bus OSC signal by 4 for use as the YM3812 Master clock 3.57954MHz. Frequency is NTSC …

Thank you very much! Although the copper tracks are very similar in color, I think I can fiddle around with contrast settings or such, otherwise things look very good indeed! I may have to ask some things that I cannot figure out, like some resistor color codes that are not obvious, and of course …

Interesting to see the clone chip. I did not download the Realtek files as they were Windows executables (not much use on Linux now...) I had a broken sound card which had a real YMF262 chip but the DAC was a clone with a name of LS-215, very similar sounding to the original YAC-512, just the …

Keropi can you please post detailed pics of both sides? Two of the front side pictures linked above were quite perfect, and they were from different PCB revision. However, the only picture from the back side was not that good as the PCB tracks cannot be seen clearly. So if possible the PCB tracks, …

Can someone with a scanner or digital camera post pictures of both sides of the Adlib card? Or preferably send me one :) Seriously, the components are so simple but to recreate the schematics I need to look at both sides of the PCB. Images I have already found are too grainy to see anything from the …

Hmm, you're right, that's how it should be done. I was under the impression it was mpu401_event() function's responsibility to check if it should raise the IRQ. So the best would propably to keep the rx buffer in mpu401, and have a exported member function which adds data one byte at a time in the …

Alright, I finally signed in. I suppose this is out of topic now, so do say if we should continue in another forum than DosBox General. I've gotten this far: 0) For now, I'll settle with the UART mode of MPU-401, because I am not familiar with the Intelligent mode at all, and won't even think about …