Physikant wrote on 2023-04-19, 09:22:

Hi Guys, I found some issues with the Intro (so the music directly after the start of the game) of Civ1. I remember the intro fr […]
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Hi Guys,
I found some issues with the Intro (so the music directly after the start of the game) of Civ1.
I remember the intro from my childhood and it's one of my favorite dos tunes.
In the Sound Blaster version, most OPL playback devices seem to have an issue: The music begins with a high pitched, constant sound, changes a few seconds later to an even higher one, and then the main music takes over. This is true for the DOSBOX-emulation as well as the playback with a standard SB16. In some cases, the main music can be heard quite silently in the background of the high pitched noise. The SB16 additionally produces some clicking noise.
You can hear this "wrong" version in this youtube-video from 0:04 to 0:17:
https://www.youtube.com/watch?v=PtK388b9drE
In my memories, the main music is the prominent tune from the beginning with the high pitched note in the background. A playback on a MT-32 proves this memory, as this "correct" playback can be heard there, too.
Here is the MT-32 version (compare here 0:06 to 0:20):
https://www.youtube.com/watch?v=IrRGfHArMNA

First off, you can't compare with MT-32 as that uses a completely different synth method. The only card that will sound the same is the Roland LAPC-I.

It is however valid to compare with your old Aztech card. Which "standard SB16" do you have? This could be CQM vs OPL3 difference...

My childhood sound card was an Aztech Sound Galaxy Business Audio 16 (I38-MMSN805), based on the AD1848 chipset, and didn't have this flaw. Sadly, i don't have it anymore and this card seems to have become far too expensive for me.

The AD1848 is just the codec for the card. The actual controller was undoubtedly an Aztech chip, probably the AZTSSPT0592-U01. I've never heard of the MMSN805 / SG Business Audio 16 before, and it's not documented here or here, but the name sounds plausible and matches an AD1848 codec.

Now, Civ 1 doesn't actually support SB audio, just AdLib, so the Aztech controller isn't relevant here, but whatever FM synth there is. Aztech used Yamaha OPL3 or 1:1 clones on all 16b Sound Galaxy cards.

Apart from analog filters, that would give identical sound to an SB16 with the same OPL3 chip. So if you notice a big difference, I'm suspecting your SB16 doesn't have an OPL3 and instead has integrated CQM FM synth. It's generally considered worse and less refined than the OPL3 it imitates.

Does anyone have a suggestion for a fix or a different sound card without the issue?

If my suspicion is correct, any card with real OPL3 or 1:1 clone would do the trick. That means the vast majority of cards:

- Creative SBPro2 or early SB16/AWE32
- any Aztech-based card
- any OPTi 929/930-based card
- any Crystal CS4232-based card
- any ALS007, 100 or 100+-based card
- any CMI8330-based card
- quite a lot of others too...

So: check which SB16 you have (CTxxxx - number) and look it up here. If your model is red in the "FM chip" column, my suspicion is probably right and the comments above apply. If it's green, something else is going on.

Thanks for the long answer. Of course comparing an OPL-generated music to a MT-32 looks invalid, but my point is: from the MT-32 version you can derive if the high pitched notes at the start are the intended sound or not.
My SB16 is a CT1740, DSP version 4.05, so real Hardware OPL, although OPL-3.
I really was surprised how rare my old card seems to be, but it really exists and is sold here:
https://www.ebay.de/itm/255766183578
So sadly, this is not an OPL vs. CQM-Issue.

That's one weird card, even by Aztech standards. Still, whatever else it is/does, that's a real OPL3 on it, and there's on on the CT1740 too, so agreed, this isn't OPL vs CQM.

I found that using the civ sound tool (that was not originally supplied with the game but released later) and changing the sound to the now available SB16 output gives the correct intro, although it sounds different from the Adlib/SoundBlaster-Option. It's more polyphonic and the clicking sounds are gone, but I don't know why: it just sounds cheaper and I like it less than the classic Adlib/SB version. So it looks like SB16 is not completely backwards compatible (and DosBox emulates a SB16, not a SB classic). Looks like for the complete retro experience, I need a SB Classic/Pro or some card thats closer to them than the SB16 (and by accident, my old strange Sound Galaxy did that).