It can be separated. As Qbix said:

use adlib.cpp as guideline on how to interface with it

ok I think Im getting understand. But if I only use this file and calling "OPLWriteReg" with commands, it wont give me any sounds for me. The mixer is needed too, isnt it?

You'll need YM3812UpdateOne to grab the sound data.

I think we misdirect each other again 😀 it doesnt use the mixer

it doesnt use the mixer

Do you read what i write?

yes.... then I just dont get it yet 😖 lets see what I see: ymf262 changes the chip's states and YM3812UpdateOne puts the whole thing into a buffer (what is allways being played) but someone must call that update function (as it is happens inside OPL_CallBack). As I see:

opl.chan=MixerChan.Install(OPL_CallBack,rate,"FM");

this installs that callback function but, to make it simple: as I browsed the code, it turned out for me, it only gives an object. Hm, who calls that CallBack function and when (how frequency, how often)?

I ashame of all "stupid" thing I might said, I know youre programers mainly and not here to deal with stupid users's stupid problems, and thanx your patient in advance

but someone must call that update function

Think you can call that function at millisecond (==tick) resolution.
The length parameter of that function is the number of samples
you want to read, set that to freq/1000 or so (freq==samples/second).

Well I can say we wasnt suffering with it in vain 😊 I see it emulates 3 chips (deepends on the #defined type) what are the differences?

Irrelevant, just choose one (3812).

10 years are ancient times for a compiler.

You can´t believe that the programmers doesn´t use newer C/C++ features in the time between. Best is that you use a newer compiler.

sadly Im delphi/pascal expert and yes I know about the compiler's differences. I just heard that its a legendary, well used C++ compiler so I tried to compile this and debug the DOSbox. 😁

One more question: the last editing in fmopl.c was in 14-06-2003 but... DOSbox's sound emulation was improved. (the differences are hearable by versions to versions). Then I dont get it. And as I see DOSBOX doesnt use this unit... Im wrong? Anyone clear me up =)

the opl part hasn't been changed since that date.
Offcourse the soundblaster stuff regarding dma transfers and the internal mixer of dosbox has had several changes since then

then I cant imagine how can the FM music be different from the first version to now 😖 its all deepend on the mixer?

what first version? and not sure what you want at all by this, use the newest and be happy