I have a ISA BTC 1817D card with the infamous OPTi82C931 Chipset (OPTiFM™)
AMAZING Full Specs here!! 🙄

For many years (1997-2002), the FM music sounds really good to me, but today, I made a comparison with a SB16 (CT1770)
and the verdict, my memory tricked me... 🤣
Opti sounds very weird, not awful, just weird. 😐

I will try to recap both cards for sound sake! 😜

Some other games/programs with awesome FM Music to test.😉

- Tyrian 2000 (Alexander Brandon masterpiece & Andras Molnar LOUDNESS engine, pure bliss) 😎
- Reality Adlib Tracker (the finest FM tracker ever made, try to hear the fantastic ALLOYRUN.RAD file )

Regards!

Disregard all OPL dorkery and keep going 👍

(if someone could decap and write a CQM emulator that'd be cool too. The common Creative OEM consumer fm playback must be just as importantly preserved)

I have several old AWE64 flacs hanging around my drive somewhere I could probably drop here (recorded directly to file)

I can't find anything CQM on wavetable.nl, anyone found any?
Although I can install my SB16 CT2950 and have few recordings.

Found my old thread with Doom E1M1 comparison.
How accurate is the OPL emulation in dosbox?

CQM doesn't sound bad at all, it's just slightly different.
Yes, one can definitely enjoy a CQM and forget completely about the "CQM vs OPL3" debate, but for the trained ear and nostalgic purposes, nothing beats a true OPL3 core.
I don't see a reason to emulate a CQM even for archival purposes, it will be an inaccurate copy of a copy... 😵

James-F wrote:

Found my old thread with Doom E1M1 comparison.
How accurate is the OPL emulation in dosbox?

CQM doesn't sound bad at all, it's just slightly different.

In E1M1, sure. But what about that Dynablaster example? 🤣

leileilol wrote:

(if someone could decap and write a CQM emulator that'd be cool too. The common Creative OEM consumer fm playback must be just as importantly preserved)

That's a perspective I've not considered, as my quest has been Yamaha OPL, but writing a bit-perfect OPL emulator has lost its appeal as there's just too many of good enough for general use emulators.

But I might add CQM to my todo list. Most likely there is no need to decap, at least I would not know much what to achieve from it.
I have no microprobing equipment, but the photos might reveal some waveform ROM contents though.

Step 1) Attach hardware to allow bit-perfect digital capture of CQM output
Step 2) Generate register data for test sounds, record generated sounds, analyze them
Step 3) Figure out algorithms that produce identical data
Step 4) Patch existing FM emulator with CQM algorithms instead.

Jepael wrote:

but writing a bit-perfect OPL emulator has lost its appeal as there's just too many of good enough for general use emulators.

There is one here on Vogons and it's part of the SVN-ECE fork by Yesterplay80.
NukedOPL by the user nukeykt is a bit perfect OPL3 emulation.
AUDIO - Nuked OPL3 Patch for DOSBox(+Windows build) (SDL1)

nukeykt has all the equipment and programming experience to recreate a bit perfect CQM from his existent OPL code.

James-F wrote:

There is one here on Vogons and it's part of the SVN-ECE fork by Yesterplay80. NukedOPL by the user nukeykt is a bit perfect OPL […]
Show full quote

Jepael wrote:

but writing a bit-perfect OPL emulator has lost its appeal as there's just too many of good enough for general use emulators.

There is one here on Vogons and it's part of the SVN-ECE fork by Yesterplay80.
NukedOPL by the user nukeykt is a bit perfect OPL3 emulation.
AUDIO - Nuked OPL3 Patch for DOSBox(+Windows build) (SDL1)

nukeykt has all the equipment and programming experience to recreate a bit perfect CQM from his existent OPL code.

Nuked OPL3 is based on black-box testing of YMF262 connected to the Arduino. There is YMF262 die shot on siliconpr0n.org. But it's quality is not acceptable for such deep analysis.
Does CQM has digital output? I thought it had integrated DAC.
I'd possibly tried to emulate it, but i have no any card with CQM and i'm busy with OPN2(YM2612, YM3438, YMF276) emulation. Fortunately there are high quality die shots of OPN family chips(YM2203, YM2610, YM2612) and YMF276 has purely digital sound output. Probably some OPN2 findings will be incorporated into Nuked OPL3.

nukeykt wrote:

Probably some OPN2 findings will be incorporated into Nuked OPL3.

This is interesting, such as what?
I thought your OPL3 is bit-perfect and complete?

If your efforts will result in a bit-perfect OPN2, I'd really like to see it eventually in KEGA Fusion.

James-F wrote:

nukeykt wrote:

Probably some OPN2 findings will be incorporated into Nuked OPL3.

This is interesting, such as what?
I thought your OPL3 is bit-perfect and complete?

I meant if i'll find them. There are a lot of common things between Yamaha chips. Initially i started with black box testing of YMF276 and wrote initial code which is heavily based on OPL3 code. It's already sounded very good. Recently i started analysing die shots. I've already determined most registers on the die. Now i'm working on envelope generator.

Except LSI test register Nuked OPL3 should be complete. Also there are no any known sample where Nuked OPL3 sounded off, so i'd say it ranges from nearly perfect to bit perfect(all my tests gave bit perfect output, but probably they don't cover all cases).

leileilol wrote:

I have several old AWE64 flacs hanging around my drive somewhere I could probably drop here (recorded directly to file)

Cool, post 'em up! I'd love to hear other recordings, especially if it's something I might not know.

I did a few more last night but something was buzzing in my setup that I didn't notice, so I have to go back and fix that. Here's one I recorded this morning:

Madbrain - Oskari Leads the Investigation (Adlib Tracker 2 in OPL3 mode. 100% CQM, no samples or digital audio used.)

Didn't use minidisc this time; sound went straight from the AWE64 through an analog mixer and into an Digi 002 Rack firewire interface & I recorded it on a Mac Mini running Ableton.

I'll also take requests if you guys have anything you wanna hear (note: stick to INTERESTING music, I'm not gonna do Doom E1M1 or Commander fucking Keen. 😜 )

nukeykt wrote:

(all my tests gave bit perfect output, but probably they don't cover all cases).

A torture test is not hard to create using AT2.
Where it can go wrong is in the 4-Operator mode where more complex wave forms are created.
Did you test with the worst possible combinations of feedback and pitch in 4-op mode?

nukeykt wrote:

Nuked OPL3 is based on black-box testing of YMF262 connected to the Arduino. There is YMF262 die shot on siliconpr0n.org. But it's quality is not acceptable for such deep analysis.
Does CQM has digital output? I thought it had integrated DAC.
I'd possibly tried to emulate it, but i have no any card with CQM and i'm busy with OPN2(YM2612, YM3438, YMF276) emulation. Fortunately there are high quality die shots of OPN family chips(YM2203, YM2610, YM2612) and YMF276 has purely digital sound output. Probably some OPN2 findings will be incorporated into Nuked OPL3.

I just looked at the Nuked OPL3 code. Found myself mentioned in the thanks section, I appreciate it 😀

CQM DAC should be separate DAC on boards that also have separate audio codec.
For example CT1747 should have external CQM DAC.

James-F wrote:

A torture test is not hard to create using AT2. Where it can go wrong is in the 4-Operator mode where more complex wave forms ar […]
Show full quote

nukeykt wrote:

(all my tests gave bit perfect output, but probably they don't cover all cases).

A torture test is not hard to create using AT2.
Where it can go wrong is in the 4-Operator mode where more complex wave forms are created.
Did you test with the worst possible combinations of feedback and pitch in 4-op mode?

Unfortunately 4 op mode is mostly untested because i never used it. But i think it should be ok. Adlib Tracker 2 SDL already uses Nuked OPL3, so developers likely checked it in various songs.

Jepael wrote:

I just looked at the Nuked OPL3 code. Found myself mentioned in the thanks section, I appreciate it 😀

CQM DAC should be separate DAC on boards that also have separate audio codec.
For example CT1747 should have external CQM DAC.

Thanks.
You right. Ct1978 has a tda1387 dac.

Supaplex on cqm and tempest 2000 on cqm have HUGE differences. as in a whole OCTAVE on some fm instruments. no joke.

i see you actually did tempest 2000, though i'm too late to grab it. i actually think it was composed on a QCM card. that's why it soudns good.