Opti 82c931
Jacque Waiden
The DOS drivers that come with these OPTi-based cards are only extracted once the Windows 3.1 setup routine has been run. This Windows setup utility will update your AUTOEXEC.BAT file to set the BLASTER environment variable correctly and automatically run the card's DOS initialisation utility, SNDINIT.EXE. I've read on Vogons that the the third-party UniSound DOS utility will also work with it, given that the card is Plug & Play.
Since I haven't actually run any installation routine, there have been no changes to my AUTOEXEC.BAT file, though I still have the SET BLASTER= line present from when the system had a different sound card in my retro PC.
As mentioned, the main program here is SNDINIT.EXE, which pulls the configuration from both SOUND16.CFG file in the driver's subdirectory and the card's EEPROM chip and initialises the card ready for use. It doesn't remain in memory which is good, but the card does need to be initialised or it won't be detected at all. The only lines added to AUTOEXEC.BAT are:
NSSI is a clever utility that uses a number of detection routines to try to find your hardware (certainly a lot more than a game would try and do when looking for your card). What is interesting is that the card is shown by NSSI as being from ExpertColor, as I suspected.
After running SNDINIT, NSSI properly detects the card using more traditional means, providing details on the port address, IRQ, DMA channels, and DSP version (equivalent to what a Sound Blaster Pro card would return):
But I'm jumping the gun a bit here. When you run SNDINIT without the '/b' command-line argument, you are presented with a fairly horrible DOS 'Windows-like' interface to configure the card's settings. Here's a video of SNDINIT running:
So the sound test ran the .WAV file audio just fine. However, configuring some games resulted in no FM synthesizer output (music) being heard, only sound effects. I then considered the card might require -5V on the ISA bus, and my current motherboard (a PC Chips M590) was setup to use an ATX power supply that doesn't provide this. I switched to the AT P8/P9 connectors, since this mobo provides both options, and noticed quite a significant increase in output levels, though still with no actual audio being heard - just an almost inaudible hiss.
At this point I was ready to chalk my findings up to a faulty card, but pressed on. Instead of initialising the card using the OPTi 82C931 SNDINIT utility, I ran JazeFox's UniSound, and this worked perfectly:
To test the quality of audio output from this card, I ran some DOS games from around the period of time this card was being sold. The majority of the games were configured for Sound Blaster Pro (if available as an option), or Sound Blaster (if not). It's possible that configuring some games for Sound Blaster Pro (stereo) actually just run standard Sound Blaster (mono) audio.
I'm fairly sure this card cannot be run in a combination of SBP and WSS mode at the same time (SNDINIT and the user guide kind of implies this - you set the mode and that's what you get in terms of compatibility), but will check this to be sure.
Given that I recorded the videos below in lossy MP4 format, I created separate recordings in .FLAC format. This allows me to check the card's frequency response and signal-to-noise ratio. I'm testing a signal-to-noise plug-in for Audacity which uses the ISO-226 curve for signal and ITU-R 468 curve for noise, the results of which are shown here:
The card exhibited no problems with reverse stereo, and the only glitch I came across was in TIE Fighter, where the FM audio would drop to silence every 30 seconds or so. I recall having the same problem with my Yamaha Audician 32 Plus card with at least one other game (Dune 2) - I have no idea what causes this - perhaps a buffering issue, but why only on certain games?
On average then, the card's weighted line-out SnR was -60.6 dB, and the speaker-out SnR was -69.9 dB, which is strange as for line-out this is poor, but for speaker-out this is actually rather good. Most of the line-out SnRs I tested would never typically be lower than the speaker-out SnR, since the onboard amplifier that drives the higher signal for speaker-out introduces more noise in the output) - I assume this is just the slight differences between the two audio recordings (line-out recording vs speaker-out recording). The spectrograms tell you the real story, and using the line-out was, as expected, a noticeably lower volume since it's unamplified, but a visibly cleaner signal compared to the speaker-out.
This is one rare sound card where actually using the Speaker-Out produced better results (in my opinion) than using Line-Out - it was clear and crisp, with little to no background hiss or hum. As I mentioned earlier, all unused lines such as MIDI, CD, MIC, etc., were muted to ensure noise was kept to a minimum.
There's no doubt the OPTiFM flavour of OPL3 comes out more 'bright' than the softer Yamaha. While this provides a perceived higher clarity, that's not a good thing as it shows up the flaws in how it tries to synthesize the instruments. Yamaha's YMF262 seems to hide these flaws by 'cushioning' the sound a little, taking off the rough edges the OPTi doesn't. On the whole though, OPTi FM doesn't offend the ears and in some titles you'd be hard-pressed to really notice much difference.
Hi there, long time lurker, first time poster here! A while ago, I came across Phil's Computer Lab youtube channel and it got me all fired up for some DOS retro gaming. So I dusted off my old PC and installed DOS 6.22 on it, but soon realized that it came with an SB128 PCI card which has some truly awful FM synth emulation. After a quick search in my local classifieds, I found a couple of ISA sound cards that seemed perfect for my needs, one of which was this OPTi 82C930. I have been using this card for several months now and was quite impressed by what it had to offer.
From what I can tell, pretty much everything that Phil mentions in his excellent OPTi 82C929 video applies to the 82C930 as well. However, I did notice a few additional details that might be of interest to anyone who has one of these OPTi cards.
I use A220 I5 D1 P330 T4 when running this card in SBPro mode under DOS, as that seemed to give me the best compatibility. As for its Windows Sound System (WSS) mode, I found it best to use port 530 IRQ 7 and DMA 1 as that seemed to work fine with the vast majority of games that support WSS. I also found it helpful to mute any unused inputs (e.g. line in and mic) via SNDINIT.EXE in order to minimize noise. Setting the volume sliders to 80 or lower also helps with that. Lastly, be sure to use the Line Out port when connecting the card to a set of powered speakers.
The OPTi 82C930 can operate in 2 modes: Sound Blaster Pro (default) and Windows Sound System. When running in WSS mode, this card can provide crystal clear 16-bit sound (samples attached below). You can switch between the two modes at any time by running SNDINIT.EXE. There is no need to restart your computer after making the switch.
Contrary to popular belief, a decent number of DOS games do support Windows Sound System. Despite its name, WSS works just fine in pure DOS and you don't need to have any version of Windows installed to make use of it. Note that it's sometimes called "Microsoft Sound System" in setup options, but it works all the same. I also found it helpful to add the following line to AUTOEXEC.BAT as it helps some games and programs to better detect WSS:
For clarity, 530 = WSS port; 1 = WSS playback DMA; 7 = WSS IRQ and 1 = WSS recording DMA. I realize that most DOS games used 8-bit sound samples, but I did notice increased clarity when using WSS instead of SBPro in some titles that were released during the last years of DOS. For reference, here are some of the games that I have personally tested on this card using its Windows Sound System mode.
Overall, my suggestion is to select WSS mode whenever a game supports it in setup, in order to get the clearest possible sound out of this card. Interestingly, certain games like Turrican II even support a 48 KHz sampling rate in WSS mode.
From reading various posts here, I have learned that you can transplant WSS drivers into some games which use the Miles sound system, even if they don't natively support WSS. Results will vary of course, but I had pretty good success so far. For reference, I used the WSS driver from Settlers 2 Gold as the source. By copying SNDSYS.DIG to other games, I was able to add WSS to the list of sound card options that are available during setup. Simply placing SNDSYS.DIG inside the folder where the rest of the .DIG files reside was enough to make WSS appear as a valid option. I did not have to overwrite any other files with it.
I did encounter compatibility issues with a couple of games when using this card. It was mostly related to Epic Megagames releases (see below) which didn't want to recognize it as a proper SBPro. They still worked with the "Sound Blaster Clone" setup option, but that resulted in lower quality sound.
However, as I have been using the DOS drivers from this site I noticed a couple of extra zip files in that archive: EPICFIX.ZIP and HMIGAME.ZIP. Turns out these two files contain the sound fixes for the following games:
Before applying these fixes, I was only able to select "Sound Blaster Clone" and "High Quality" in all of the Epic games mentioned above. After applying the fixes, I can now select "Sound Blaster Pro" and "Ultra High Quality" and all those Epic games work perfectly, providing much cleaner sound then before. Descent also works fine in SBPro mode with the HMIGAME.ZIP fixes applied, though I still prefer to run that game in WSS mode for even better audio quality.
Back in the day, I remember dismissing most clone cards and arguing with my friends that a genuine SB16 was the only way to go. I'm very glad to be proven wrong. The SBPro mode of this OPTi card is great for DOS games from the early 90s, when Creative's SBPro was king. For later games, WSS is the preferred option as you can get 16-bit sound, when it is supported. The FM synthesis on this card sounds great, and the drivers come with a nice GUI which makes it easy to configure everything in seconds. Overall, I'd say the OPTi 82C930 is a pretty solid, cheap solution for DOS retro gaming with some interesting extra features that make it stand out in a good way.
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