Very interesting project! My PC Chips M571 motherboard has an integrated sound card based on the (similar?) CMI8330 chip, and I was really impressed by its capabilities. A few questions:

1. What are the differences between the CMI8330 and CMI8830 chips?
2. Is the 1:1 OPL3 compatibility fully confirmed? It sounded pretty much the same to my ears, but I never did a detailed waveform comparison or something like that
3. Does this card lack ADPCM support? This was one of the very few downsides of my integrated CMI8330
4. Can IRQ/DMA resources be shared between the SB and the WSS portions of the card? My integrated one could not do this using the stock drivers, so it ended up taking a whole lot of resources
5. Is the HRTF support based on Sensaura? If not, does it support A3D 1.0? I never got to properly test this on my integrated card
6. Some CMI8330 based cards (including my integrated one) had an issue where it was not possible to use a joystick connected to the gameport due to a missing resistor or something. I imagine there is no such problem with this card?

Anyhow, great idea for making a modern sound card using these chips. From my experience with the CMI8330, it has extremely low self noise, an incredible compatibility range (SB, SBPro, SB16 and WSS), superb sounding FM synth and a bugfree MPU-401 interface. I don't think I've seen such a feature set on any other sound card.

does the PC MIDI addon work on PC/104?

@Joseph_Joestar

1. great catch! ofcourse 8830 is a typo , the card is the 8330 🤣 I have fixed the typos now...! 🤣
2. well if it sounds the same then it probably is the same 😉 I mean it would not be that unrealistic that the LS262 stolen design is integrated into CMI8330... but no I did not do any waveform comparisons because quite frankly I could not detect any difference. Even Dynablaster that sounds weird in "opl compatible" chips sounds the same as if there is a yamaha part on the card.
3. sadly there is no SB ADPCM support so Duke Nukem 2 for example won't play SB sfx
4. nope, each standard gets it's own resources , they cannot be shared as per chip design. Maybe some software trick exists but it's certainly not normal to operate with shared resources.
5. it is sensaura tech but it predates A3D AFAIK , I cannot say I really bother with such old "3D enhancements" as they are somewhat of a gimmick in my book... still it exists for people that like such things.
6. no such issues with the MK8330 , joystick works as expected

I also feel the same for this chip, it is very much functional for our retro-gaming needs. It certainly cannot offer the sound quality of the CS4237 for example but it is more than enough to enjoy a couple of games.

imi wrote on 2022-04-14, 20:17:

does the PC MIDI addon work on PC/104?

bus pinout matches but it is totally untested

Looks very promising! I definitely want one with the addon card. Those features makes it one of the best Sound Blaster clones but the addon card should have had one extra OPL so dual OPL would have been possible with single card.

keropi wrote on 2022-04-14, 20:19:

2. well if it sounds the same then it probably is the same 😉 I mean it would not be that unrealistic that the LS262 stolen design is integrated into CMI8330... but no I did not do any waveform comparisons because quite frankly I could not detect any difference.

This has been my experience as well. I tried several games and could never hear any differences between the CMI8330 and my YMF744 card which of course has genuine OPL3. A waveform comparison using SPDIF out on both cards would offer additional proof, but sadly, my integrated CMI8330 only has SPDIF in.

5. it is sensaura tech but it predates A3D AFAIK , I cannot say I really bother with such old "3D enhancements" as they are somewhat of a gimmick in my book... still it exists for people that like such things.

I'm mostly asking because the CMI8330 manual which came with my motherboard (attached here) mentions A3D specifically, but I never got to testing it. That said, this manual is a bit more detailed than the ones for standalone CMI8330 cards. Feel free to take a peek in case there's something useful for you guys inside.

Awesome, I've never found a card with this chip in the wild. The ALS100 might be slightly better on paper as it supports ADPCM, but I've never gotten a card with that chip to work.

Could you tell a bit more about how the audio quality of the chip is inheritly limited (at least, that's the idea I get).

Also really cool that this is an actual finished product almost ready for sale.

@Joseph_Joestar
thanks for this manual... it certainly is more well written than the other stuff I have seen
what software wavetable solution your system uses? do you have it installed? it is mentioned in the datasheet as well but there was no such download in the old CMI site... so I am curious what they licensed back then

@Oetker
both CMI8330 and ALS100 chips were mainly used by random manufacturers doing dirt cheap soundcards... this is especially true with ALS100 - I also had a couple cards that did not work correctly: it was not the ALS100 that failed but the opamps and their low quality cheap components.
There is nothing wrong with the CMI8330 but for example the CS4237 does sound better. It is just a better made chip with more features whereas the CMI one was aimed at OEMs that needed cheaper options. The internal OPL clone is certainly a very nice touch. As-is the MK8330 sounds better than the majority of old soundblaster cards - so it is pretty usable and enjoyable.

I am sure there will be some games that won't work with SB16 mode or will have some quirk but that's the nature of compatible chips. From experience with the megacard the CMI chip has a little better SB16 compatibility and sound quality. ALS100 lacks WSS support but adds SB ADPCM playback.

Awesome! I really appreciate your work. Do you plan to produce and distribute the card for us, like you do with the Oprheus?
I can confirm CMI FM sounds the same as the Yamaha OPL3, made a comparison video once:
https://youtu.be/cZpzgJGZmnc
(OPL2) and here (OPL3)
https://youtu.be/pjz9or5VqDQ

keropi wrote on 2022-04-14, 21:10:

what software wavetable solution your system uses? do you have it installed? it is mentioned in the datasheet as well but there was no such download in the old CMI site... so I am curious what they licensed back then

My M571 motherboard is currently in storage, so I can't check right now. From what I remember, the software wavetable sounded kind of crappy.

BTW, the driver CD for that motherboard can be downloaded from this website. Among other things, it contains the CMI8330 DOS and Win9x drivers, as well as the manual that I linked to earlier and the software wavetable utility. IIRC, all that stuff is in the SoundPro folder, which is what the motherboard manufacturer called their integrated CMI8330 solution.

Incredible work as always! <3

pc-sound-legacy wrote on 2022-04-14, 21:44:

Awesome! I really appreciate your work. Do you plan to produce and distribute the card for us, like you do with the Oprheus?
[...]

yes indeed - this is the plan 😀

Joseph_Joestar wrote on 2022-04-15, 04:02:

My M571 motherboard is currently in storage, so I can't check right now. From what I remember, the software wavetable sounded kind of crappy.

BTW, the driver CD for that motherboard can be downloaded from this website. Among other things, it contains the CMI8330 DOS and Win9x drivers, as well as the manual that I linked to earlier and the software wavetable utility. IIRC, all that stuff is in the SoundPro folder, which is what the motherboard manufacturer called their integrated CMI8330 solution.

thanks for the info again ! yeah it is expected that the software wavetable would be crappy - it would be something cheap.
I can see that they have it embedded in the driver installation but it looks like CMI released newer drivers v2.0 so I assume they would be better to use under win9x
Actually the main bulk of the chips we acquired have the SoundPRO marking - they kinda look better 🤣
So the final version cards will have these chips soldered.

keropi wrote on 2022-04-14, 21:10:

There is nothing wrong with the CMI8330 but for example the CS4237 does sound better.

So when comparing to Orpheus, you get SB16 support at the expense of sound quality? That would mean that if you have GUS, then Orpheus would be better for Sound Blaster stuff since there is very little, if any, need for SB16 support if there is GUS (and WSS from the Orpheus). So MK8330 could be good alternative to Orpheus mainly on systems with only one ISA slot?

aitotat wrote on 2022-04-15, 07:30:

So when comparing to Orpheus, you get SB16 support at the expense of sound quality? That would mean that if you have GUS, then Orpheus would be better for Sound Blaster stuff since there is very little, if any, need for SB16 support if there is GUS (and WSS from the Orpheus). So MK8330 could be good alternative to Orpheus mainly on systems with only one ISA slot?

Both are good - but the CS4237 is just on another level in both features and output. They just targeted different market levels, one for OEMs that needed cheaper solutions and the other had the potential to be used in more advanced cards. It the end of the day it's up to the end user to decide which features are more appealing for their system and needs.
This is just one more choice out there , the goal was to make something that would rival the mid-tier cards one can get on eBay while offering better results.

aitotat wrote on 2022-04-15, 07:30:

So when comparing to Orpheus, you get SB16 support at the expense of sound quality? That would mean that if you have GUS, then Orpheus would be better for Sound Blaster stuff since there is very little, if any, need for SB16 support if there is GUS (and WSS from the Orpheus). So MK8330 could be good alternative to Orpheus mainly on systems with only one ISA slot?

From what I remember, and I could be wrong since it's been a while, the WSS compatibility of the CMI8330 is slightly better than that of the CS4237.

I think my integrated CMI8330 worked fine with Sierra WSS games like Gabriel Knight out of the box, while the Orpheus apparently needs some additional patches/fixes.

This looks great yet again! 😀 Happy to see that the CMI8330 is being used on a properly designed sound card for a change.

Are there any plans to offer a bundle that includes the Dreamblaster X2GS? I'm already a happy user of the Orpheus + X2, but I've been looking for an excuse to buy an X2GS. This might just be it 😆

From our point of view, and seeing what most people want or need (we are not talking about particular sound card features, but generic).
We found that CMI8330 fills most needs for a good cost. Of course there are compromises, or we wouldn't be doing such cards.
But CMI8330 is one of the chips with less compromises.
I only see advantages in this chip.
-SBRO2
-WSS
-SB16
-SPDIF out (DIGITAL and FM)
-SPDIF in
-3D Surround(basic)
-Good OPL3 (identical to Yamaha, my ears cannot fell the difference).
-Software is easily configurable.
-No TSR
People complain about not having ADPCM, but most of those games have patches, and they are not so many. WSS games are much more abundant than ADPCM games.
The advantages of this card we made are basically these:
-14.31818 Mhz Crystal on board
-Spdif IN and out on board ready for connection
-Joystick circuit is fixed
-Upgradable with a PCMIDI daughter board .
-You can fit a full length Wavetable board.
-Board looks nice 😉
So I hope you appreciate this card the same way we do 😀. If you don't like it's good ok, there is always space for improvement and other nice cards around!

Lennart wrote on 2022-04-15, 12:21:

This looks great yet again! 😀 Happy to see that the CMI8330 is being used on a properly designed sound card for a change.

Are there any plans to offer a bundle that includes the Dreamblaster X2GS? I'm already a happy user of the Orpheus + X2, but I've been looking for an excuse to buy an X2GS. This might just be it 😆

I think Keropi can answer you better, but I think you can get one with this card ! 😁

Lennart wrote on 2022-04-15, 12:21:

[...]
Are there any plans to offer a bundle that includes the Dreamblaster X2GS? [...]

ofcourse there will be a bundle option 😀

keropi wrote on 2022-04-15, 12:45:

Lennart wrote on 2022-04-15, 12:21:

[...]
Are there any plans to offer a bundle that includes the Dreamblaster X2GS? [...]

ofcourse there will be a bundle option 😀

Good to hear, I'll be keeping a close eye on this thread then 😉