VOGONS


AdLib Gold Questions

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First post, by 640K!enough

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I finally decided to get my old AdLib Gold out of storage to see if it really sounded as good as I thought I remembered. So far, the results haven't exactly been what I would have hoped for. Of course, the machine I am using is far newer than what was available at the time of the AdLib Gold, and that seems to be causing most of the problems.

Initially, about the only thing I could do well was load the control chip driver and update the configuration; everything else would fail. The FM timer tests resulted in a rather loud, distorted buzzing that persisted after the test completed. The FM tests produced noise louder than the output, and trying to play RL2 files resulted in noise, missing notes, distorted instruments and PCM percussion that was (sometimes) either truncated or outright missing.

I decided to try changing a few settings, to see if that would improve the situation. Increasing the 8- and 16-bit I/O recovery time helped; the FM timer tests passed consistently. Increasing it more allowed the MMA timer tests to pass, too. However, trying the timer tests again after using the Jukebox Gold software still has the MMA timer tests failing (usually timer 0 and the concurrent timer tests); FM timer tests are still fine. Is this a peculiarity of their software, or do the timer tests usually still pass after using the RL2 player?

I also noticed that their software is somewhat inconsistent. In the setup application, it is possible to specify that an IRQ should not be used, and it is supposed to default to software polling. However, even with that selected, some software still seems to read it as having an IRQ selected, which caused trouble with the device that was actually supposed to be using those resources. I gave it its own IRQ, but neither improves the timer test situation.

I suppose there could be something wrong with my board, but I suspect finding ways to slow down my system further would help with the MMA timers. Disabling all caches still wasn't enough, so what tools do you generally like for providing additional speed reductions in situations like these?

I still have the card, but haven't managed to find the original software diskettes. The version on vogonsdrivers.com seems to contain most of what I remember, but there are a few things missing. I seem to remember a rather decent MOD player being included. Is there any chance someone still has that available? If it's not appropriate for vogonsdrivers, as an addition to the software package, please let me know what it was called; I'm hoping to be able to track that down somewhere.

Lastly, I'm noticing a good deal of background hiss that I don't remember from when the card was new. Is that "normal" for the Gold, possibly a result of the on-board amplifier used, or might replacing the ageing through-hole capacitors help?

EDIT: Corrected spelling error.

Reply 1 of 7, by fitzpatr

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What hardware are you trying to use it on? The AdLib Gold is solidly in the 486 vintage, so I expect that as you've surmised, and as I've experienced with the similar SB Pro 2, speed can play a huge factor.

Roughly where are you in Canada? I'm in SW Ontario, and I have a few more period correct boards.

MT-32 Old, CM-32L, CM-500, SC-55mkII, SC-88Pro, SC-D70, FB-01, MU2000EX
K6-III+/450/GA-5AX/G400 Max/Voodoo2 SLI/CT1750/MPU-401AT/Audigy 2ZS
486 Build

Reply 2 of 7, by Jepael

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Since you own such a rare card, for reverse-engineering purposes, would you be able to put the card in scanner or take sharp high-res photos of it so component markings are visible?

I'm asking this because I've written some code to emulate the add-on Surround Module, and would like to know more about how the audio signals flow in the system.

Reply 3 of 7, by 640K!enough

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fitzpatr wrote:

What hardware are you trying to use it on? The AdLib Gold is solidly in the 486 vintage, so I expect that as you've surmised, and as I've experienced with the similar SB Pro 2, speed can play a huge factor.

I actually thought I had thrown the card away, and was pleasantly surprised to find it in a storage box with some other old hardware. I decided to give it a try in the only ISA-endowed machine I have: a Pentium III 600, which is beyond what we would have imagined in the time of the AdLib Gold. When I originally bought it, the 486 was still an expensive luxury for a home user; many who had home machines at all had a 386 (usually SX) or less. Even at the time, I remember it becoming gradually more problematic as I moved to faster hardware, but I figured it was worth a shot, and still expect it can be made to work a little better than it currently does.

I also remember eventually "upgrading" to a Sound Blaster 16 and being quite disappointed by its comparatively tinny, hissy, flat sound.

fitzpatr wrote:

Roughly where are you in Canada? I'm in SW Ontario, and I have a few more period correct boards.

I'm in Quebec, so distance would tend to make trouble-shooting rather impractical.

Reply 4 of 7, by 640K!enough

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Jepael wrote:

Since you own such a rare card, for reverse-engineering purposes, would you be able to put the card in scanner or take sharp high-res photos of it so component markings are visible?

If nobody else who owns one gets to it before I do, I would be happy to help, as long as you're willing to wait a few days. I will first have to remove it from the system, and get my scanner installed again. Please keep three things in mind, however:

  1. I don't currently own a machine that allows the card to work at its best, so my ability to record audio samples or run software to test the card's behaviour will be limited.
  2. I do not own any of the add-on modules; just the base card.
  3. I will not undertake any activity that might endanger the card. For instance, I will not remove components to expose traces under them.
Jepael wrote:

I'm asking this because I've written some code to emulate the add-on Surround Module, and would like to know more about how the audio signals flow in the system.

What are you aiming to do, exactly? What is the purpose of emulating one module? If the intent is ultimately to emulate the whole card, wouldn't the control chip be a bit of a difficult undertaking?

Reply 5 of 7, by Jepael

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640K!enough wrote:
If nobody else who owns one gets to it before I do, I would be happy to help, as long as you're willing to wait a few days. I w […]
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If nobody else who owns one gets to it before I do, I would be happy to help, as long as you're willing to wait a few days. I will first have to remove it from the system, and get my scanner installed again. Please keep three things in mind, however:

  1. I don't currently own a machine that allows the card to work at its best, so my ability to record audio samples or run software to test the card's behaviour will be limited.
  2. I do not own any of the add-on modules; just the base card.
  3. I will not undertake any activity that might endanger the card. For instance, I will not remove components to expose traces under them.

I will try to keep that list in mind and respect your card and it's historical value appropriately.
Also, I am not in a hurry, so I can wait as long as necessary, I appreciate the effort to scan the card.
I've not been able to find large enough and sharp enough pictures.

640K!enough wrote:

What are you aiming to do, exactly? What is the purpose of emulating one module? If the intent is ultimately to emulate the whole card, wouldn't the control chip be a bit of a difficult undertaking?

My first goal is to be able to play music from games as they would on Adlib Gold with the surround module, just because I don't think the surround module has been emulated yet. And the surround module easiest part to start from, because OPL3 FM emulation already exists, and the surround module just post-processes the OPL3 output to get that Adlib Gold specific awesomeness. I'ts only kind of very simple DSP with multiple settable delays and gains for the audio.

No the control chip is the most simplest part really, it's just the interface how the chips and the card appears to the computer and programmer. Emulating the DAC/ADC for getting PCM sound effects from games should be much harder. But those have documentation.

The hardest part that has no documentation is how the audio is being routed, filtered and mixed together before output, and to reverse-engineer that we must take a look at component values. In fact, I don't even know if the PCM output can be routed through surround module or not.

Reply 6 of 7, by 640K!enough

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I had time to make an initial attempt at scanning the card; the images are attached. If you need higher resolution, different settings, camera shots of a specific section or similar items, feel free to ask; I'll try to help if I can.

EDIT: For those who are unfamiliar with bzip2, the image files are compressed. Linux and macOS (formerly Mac OS X) can decompress them without additional software, and 7-Zip can do the job under Windows. The only modification to the scanned images was the removal of the board serial number, for paranoia's sake.

Reply 7 of 7, by 640K!enough

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For anyone who may be interested, I found a few more images:

Card Front
Box Front
Box Back