True OPL3 output in DosBox

[endre1952]

If I wanted to drive a real OPL3 sound card in DosBox, what would be my options? There's a verison of DosBox supporting OPL passthrough. I know there are some P4 motherboards with ISA slots, but I have not seen one with DDR2 and PCI-E slots. I do have several ISA Sound Blaster cards with true OPL2 or OPL3 chips hanging around.

There are some ISA to USB adapters available, would any of those work with a sound card?

[MusicallyInspired]

Here's one. First one on the page. The MB-P4BWA. Supports Core 2 Quad processors, DDR2, SATA, RAID, 1 x PCI-Express X16, 1 x PCI-Express X4, 1 x mini-PCI, 4 x PCI, and 2-ISA slots. Haven't seen any for sale anywhere though. But it exists. I've been looking for it myself.

[Silent Loon]

If I wanted to drive a real OPL3 sound card in DosBox, what would be my options?

I use the modified version of dosbox (with passthrough) you've allready mentioned with a YMF724 based PCI soundcard (its a Yamaha Waveforce  192 clone). As the YMF724 is from Yamaha they have included the original OPL3 circuit, so it should sound the same (I think it sounds even better). This seems to me the cheapest solution (you should get a used one for around 5-10$).

[endre1952]

Thanks for the tip! I'll try to get one.

[Silent Loon]

Good luck!
When you have got it, maybe we could compare some sound samples.

I also managed to get the famous stereo SBPro 1 (CT1330) music under dosbox, which is strange, as the YMF 724 of course has only one OPL integrated.

[Great Hierophant]

If I wanted to drive a real OPL3 sound card in DosBox, what would be my options?

I use the modified version of dosbox (with passthrough) you've allready mentioned with a YMF724 based PCI soundcard (its a Yamaha Waveforce  192 clone). As the YMF724 is from Yamaha they have included the original OPL3 circuit, so it should sound the same (I think it sounds even better). This seems to me the cheapest solution (you should get a used one for around 5-10$).

I considered this same solution, but I was never able to get the YMF-724 card working with the OPL passthrough versions of DOSBox.  My OS was Windows XP and porttalk did not work to send the OPL data to the card.  In Windows 98, however, it did work.  Windows 98 does allow direct IO access to peripherals, Windows XP does not.  

Good luck!
When you have got it, maybe we could compare some sound samples.

I also managed to get the famous stereo SBPro 1 (CT1330) music under dosbox, which is strange, as the YMF 724 of course has only one OPL integrated.

But that YMF-724 can do stereo OPL3 music.  Which game were you using? 

[endre1952]

No problem, I may install a version of Win98SE just for DosBox.

[Silent Loon]

I'd also heard about the problems with XP, so I used win98 from the beginning

But that YMF-724 can do stereo OPL3 music.  Which game were you using? 

Ultima UW - seems to be the only one that uses the two OPL2s of the CT1330A for stereo music (with a Pro2 you get mono, I think). I chose the SBPro 1 + 2xopl2 options in dosbox and it works (but I don't know how - so I got suspicious that the passthrough version is not configured correctly)

[Great Hierophant]

I'd also heard about the problems with XP, so I used win98 from the beginning

But that YMF-724 can do stereo OPL3 music.  Which game were you using? 

Ultima UW - seems to be the only one that uses the two OPL2s of the CT1330A for stereo music (with a Pro2 you get mono, I think). I chose the SBPro 1 + 2xopl2 options in dosbox and it works (but I don't know how - so I got suspicious that the passthrough version is not configured correctly)

Both dual OPL2 and OPL3 can do stereo FM music, they just do it in different ways.  Perhaps the OPL Passthrough translates one into the other.

However, does your Windows machine lack ISA slots?  Porttalk certainly works with ISA devices in Windows XP, and DOS games always work better overall with an ISA card. 

[Silent Loon]

The pc I use with the YMF724 is actually based on a VIA P4MA Pro 533 board. This is a P4 mATX board that still supports AGP 3.3V cards and can thereby house my Voodoo 5500 AGP. Its mATX and there is no ISA slot (unfortunately).
My idea was to use this as a fast V5 assembly (CPU is 2.4 Ghz P4) that offers the possibility to play (very) old dos games via dosbox. MT-32 support can be achieved by using a midi / joystick adapter and plug it in the MT-32. For "true" OPL support I had this idea with the passthrough version and the YMF724. It sounds good, but passthrough and standard versions of dosbox sound very similar, maybe because the dosbox emulation is very close to the original?
I don't know how dosbox accesses the soundcard, or how the passthrough works. But could it be possible that the passthrough is not necessary, when the OPL circuit is integrated into the soundchip? The YMF724 card is a one chip solution, I guess.

[endre1952]

I did get a YMF-724 PCI card very cheap: just 1.99USD+6USD shipping. I can make recordings when it arrives.

Two questions:

Is it possible to install Win98SE on a system that already has XP and Vista on two seperate partitions?

Possible solution I'm thinking of: make a small empty partition with Partition Magic, install Win98SE on it, then restore the Vista bootloader.

My GPU in my main system is a Radeon 4650 HD PCI-E. Is there any driver for it that might work with Win98?

The card, with the DOS drivers I've found, should also work in real DOS, shouldn't it? I wonder how many DOS games will run properly on a 2.7GHZ dual core system...

I have built a 386 SX40 for retro gaming, but I don't want to build a third system that's in between.

[Great Hierophant]

The pc I use with the YMF724 is actually based on a VIA P4MA Pro 533 board. This is a P4 mATX board that still supports AGP 3.3V cards and can thereby house my Voodoo 5500 AGP. Its mATX and there is no ISA slot (unfortunately).
My idea was to use this as a fast V5 assembly (CPU is 2.4 Ghz P4) that offers the possibility to play (very) old dos games via dosbox. MT-32 support can be achieved by using a midi / joystick adapter and plug it in the MT-32. For "true" OPL support I had this idea with the passthrough version and the YMF724. It sounds good, but passthrough and standard versions of dosbox sound very similar, maybe because the dosbox emulation is very close to the original?
I don't know how dosbox accesses the soundcard, or how the passthrough works. But could it be possible that the passthrough is not necessary, when the OPL circuit is integrated into the soundchip? The YMF724 card is a one chip solution, I guess.

Okay, that does make sense.  DOSBox's OPL emulation is very good, just a bit shy of perfection with very infrequently used features such as rhythm sounds and digital sampling.  As DOSBox requires a lot of CPU power, using the passthrough mode means that it does not have to waste a significatn amount of CPU power emulating OPL. 

The passthrough driver works by sending the OPL data that the DOS game or program is generating directly to OPL hardware on your system.  If there is no OPL hardware (or hardware that is set up to emulate OPL) in your system, it will not work.  Vanilla DOSBox cannot utilize real OPL hardware in any way, it is designed to be run on as many computing devices, PC and non-PC, as possible.  Outside the IBM PC world, there is little support for OPL2/3. 

[Great Hierophant]

My GPU in my main system is a Radeon 4650 HD PCI-E. Is there any driver for it that might work with Win98?

The card, with the DOS drivers I've found, should also work in real DOS, shouldn't it? I wonder how many DOS games will run properly on a 2.7GHZ dual core system...

Apparently not in Win 9x, see here:
http://www.msfn.org/board/topic/107001-compatible-hardware-with-windows-9x/?s=262e3fbd9dda188aa56dec0474c9c3b1

VGA compatible cards, even that Radeon, which is light-years more advanced than VGA, will work in DOS without a problem and should work with most DOS games.  No drivers are required. 

[jharris01]

The pc I use with the YMF724 is actually based on a VIA P4MA Pro 533 board. This is a P4 mATX board that still supports AGP 3.3V cards and can thereby house my Voodoo 5500 AGP. Its mATX and there is no ISA slot (unfortunately).
My idea was to use this as a fast V5 assembly (CPU is 2.4 Ghz P4) that offers the possibility to play (very) old dos games via dosbox. MT-32 support can be achieved by using a midi / joystick adapter and plug it in the MT-32. For "true" OPL support I had this idea with the passthrough version and the YMF724. The YMF724 card is a one chip solution, I guess.

Will the passthrough patch work with an original Waveforce as well? Supposedly it has a YMF24E chipset. I feel very tempted to take my old computer rig out from storage and try out your approach. I did try running an official DOSBox build under win98 a few years back but wasn't very successful. The computer wasn't fast enough and Win98 kept throwing hissy fits when running DOSBox. I was never able to get DOSBox running stable. Have you run into similar problems? Also what version of DOSBox have you patched? I found a website with the patch but it seems a bit outdated.

[Silent Loon]

Will the passthrough patch work with an original Waveforce as well? Supposedly it has a YMF24E chipset. I feel very tempted to take my old computer rig out from storage and try out your approach. I did try running an official DOSBox build under win98 a few years back but wasn't very successful. The computer wasn't fast enough and Win98 kept throwing hissy fits when running DOSBox. I was never able to get DOSBox running stable. Have you run into similar problems?

The passthrough patch should work with the original Waveforce as well. I think the only difference to my oem YMF724 card is the lack of a spdif connector.

I don't know how the first versions of dosbox perform, but I never run into problems with it. You need a 1Ghz cpu as minimum for an early non-protected-mode dos game. CPU demanding games and especially SVGA games with CD-rom seem to ask for more CPU power, but in fact I had the most problems with setting the speed of the emulation right. I. e, I would still prefer UW on a 486DX33 because the scrolling and moving seems smoother. But the sound in dosbox with a YMF724 and the patch is far better.

I use hal-9000's megabuild: http://home.arcor.de/h-a-l-9000/
I use frontends for dosbox, which makes life with dosbox really easier. First I used defend, now defend-reloaded.

[rftl]

Does OPL passthrough work in Win7 64Bit?

Are there even Win7 compatible OPL SoundCards? (yeah probably not)

[jharris01]

Does OPL passthrough work in Win7 64Bit?

Don't think so. This is meant for people who want to use DOSBox using real ISA soundcards. It poses a tricky balance and yet interesting challenge (to those with the hardware to pull it off).

You see to achieve this you would need an old motherboard that has an ISA slot and yet fast enough to run DOSBox. That pretty much limits your choices to hybrid motherboards that came around the turn of the century or special motherboards made for industrial use. It also means your operating system needs to support ISA (eg. Win98/2000/maybe XP [see previous posts about this]) and still be able to run DOSBox.

That's why the interest with the YMF724 chip sound card models. In theory that would allow you to use a faster, all PCI motherboard.

Anyway hope that clears things up.

[Doctor Creep]

You would need an old motherboard that has an ISA slot and yet fast enough to run DOSBox. That pretty much limits your choices to hybrid motherboards that came around the turn of the century or special motherboards made for industrial use. It also means your operating system needs to support ISA (eg. Win98/2000/maybe XP [see previous posts about this]) and still be able to run DOSBox.

I have a Gigabyte GA-7IXE4 (2 ISA, 5 PCI, 1 AGP) with 1 GHz CPU - great hybrid-system (DOS, Win98 (sort of DOS too ), Win XP)
Will upgrade to a 1.4 GHz CPU soon - should be fast enough for DOSBox...

Details:

http://queststudios.com/smf/index.php/topic,2833.0.html

Doc

[jharris01]

Looks to me you are ready to rock and roll. If you try this out, let me know how it goes. Would love to hear what games you got running, how they sounded, etc.

[endre1952]

I'm able to use the OPL3 capabilities of the YMF-724 in true DOS mode on my very modern dual-core system. Unfortunately, I would like do use DosBox opl passthrough under XP or Win 7, which isn't possible, right?