I have used it in a 430TX mobo, and it worked well, in DOS, Win95 and Linux. By itself or coupled with a GUS ACE.
Then it worked in a 486. Then it did not work (the digital sound part) in any other mobos I tried (Socket 7 and SS7).
I'll give it one more try in a 486 system, on IRQ7. If it won't work...
then, "It's dead, Jim!"

I don't think I've ever dealt with a more frustrating card... 😵

Once upon a time, I'd hoped to pair a SW20-PC with an SW60XG in a two-slot system, which would have made for some sweet, sweet Yamaha aural goodness. And why shouldn't it? Yamaha designed them both, after all. Imagine my disappointment then, upon discovering that the SW20-PC is ridiculously noisy, all thanks to its wonderful Karaoke Processor chip (that, due to an equally ridiculous design, cannot be bypassed. Whoops!).

And so, what ought to have been a reference OPL4 design simply isn't.

Incredibly, it gets worse...

You see, recently, I figured I'd give the SW20-PC another go, and discovered something rather neat in the process: The YMZ290 chip spits out FEh (ACK) bytes. Therefore, not unlike the Ensoniq Soundscape cards, games requiring an "intelligent-mode" MPU-401 interface will also work with the SW20-PC. This is all fine and well, assuming you want to play-back MT-32 scores via the OPL4 General MIDI soundset, but who wants to do that, right? Not a problem - just hook up the ol' MT-32, via the joystick port, and...

Nothing.

Apparently, the SW20-PC does not support external MIDI in DOS. Good one, Yama-ha-ha-ha!

Cloudschatze wrote:

Good one, Yama-ha-ha-ha!

🤣
What mobo/CPU are you using? keropi mentioned earlier in this thread that this sound card works best for old systems, eg 386/486/p1. If you are using a faster machine, it's possible that some of its features are malfunctioning, eg your external MIDI in DOS testing.

yeah I never got it working correctly in anything above a pentium1.... in newer systems the dsp got crazy and the card was unusable

Time to revise a statement...

Cloudschatze wrote:

Apparently, the SW20-PC does not support external MIDI in DOS via the MPU-401 interface. Good one, Yama-ha-ha-ha!

Here's the deal...

The SW20-PC has two, completely independent MIDI interfaces.

1 - The YMZ290, "MIDI Extension Controller," which is primarily used to provide MPU-401 UART compatibility to the OPL4, when used in conjunction with a "translation" driver.

and

2 - The OPTi 82C928 itself, which is only "Sound Blaster MIDI" compatible, but handles the external MIDI TTL parallel/serial conversion.

So, there you have it. In DOS, external MIDI devices are only usable if the software supports "SB MIDI." I imagine a DOS driver could have been written to read and re-direct from the YMZ290's FIFO to the OPTi's MIDI port (similar to what is already done by OPL4DRV), but alas...

What a kludge. 🙄

The old girl is still alive and kicking. Don't know how I revived it, but I don't care.
It works perfectly on a P II/III socket 370 VIA 693 mobo.
It works perfectly on an Intel ZX mobo.
But I put her on storage since the arrival of my DB-60XG clone. I can use that with 3 ISA or 2 PCI cards from my collection. One of those PCI cards is ESS Solo based Terratec, which has almost perfect SbPro DOS compatibility. The other is an Aztech Vortex1.

you got it working fine on a PII/III mobo? wow... I could never make it work on my 440BX mobo back then... nice!!!!
you just popped it in and it worked? with what driver set?

Just the regular DOS drivers. Never bothered with Win9x drivers, having her work in plain DOS is enough for me.

Reopening an old post, but I've recently acquired such a card and I can't get the Sound Blaster compatible part to work. The card's configuration program sais it can't detect the DMA address "DMA channel cannot be detected! Check if your card is properly isntalled or reconfigure your card to a different DMA channel". The OPL4 works great - I set it to 330 and IRQ3.

Can someone lend a hand?

what system have you installed the card in? cpu? did you try the latest drivers?

I tried it on several machines. A 586, a K6-3 and a PIII. The OPL4 works fine on all machines, but the sound blaster compatible part only works on the 586 in Doom (it crashes Duke3D setup) and it sometimes works in Doom and Duke 3D on the K6-3, but it's not constant. The k6-3 uses an Aopen X59PRO VIA MVP3 board and the PSU has a -5v line.

I used the drivers of the Vogons Drivers section.

strange, it *should* work on the 5x86 pc (unless it's not a 486 variant)... don't bother with anything newer than 486 - I never got it running with anything ss7+
the drivers on vogonsdrivers are the newest you can find so you are set there

it sometimes works on the K6 - everything, including the SB-compatible part. On whatever platform I try I get the DMA error. Any ideas?

yes - too fast pc... unless the card is damaged somehow. the card has issues with fast pcs

Got it working on a K6-2 550MHz running on an AT form factor jetway MVP3 😁 - this thing sounds GOOD!

I reserved all IRQ and DMA the card uses in bios (set to "Legacy ISA") then I set "Assign IRQ "By Edge", and disabled ALL power management features, including IRQ / DMA settings. The card works flawlessly now. After doing all this I set "reset configuration data" to Enabled end rebooted. Low and behold, the card works now!

really? very nice to hear this! remember to play with the DSP, lots of fun 🤣

keropi wrote:

really? very nice to hear this! remember to play with the DSP, lots of fun 🤣

I will. I got it running on the 586 too. Again, I had to disable all power management features.

aha! so maybe that's the issue here! really nice find!

keropi wrote:

aha! so maybe that's the issue here! really nice find!

It seems so. Unfortunately I still can't get it to run reliably on my Aopen ATX MVP3... sometimes it runs perfectly, other times I get audio corruption. When audio corruption occurs in dos, the card shows up with an exclamation mark in windows. Turning the machine off and then on again fixes the problem but it resurfaces randomly 🙁

The card has a lovely sound. OPL3 sounds... different from other cards - it's much clearer to the point you might think it has soundfonts mixed in. I might actually build a machine just for this sound card or replace the SB32 in my 586 with it.

Hi, has anyone connected this card to an external midi module? The manual says:

> The MIDI/JOYSTICK connector allows connection with external MIDI devices for MIDI data
transmission and reception as well as a joystick using the optional Yamaha MIDI Adaptor
Cable (MDC-01).

I have one of those generic kind of dsub->midi port adapters which I assumed should work, but I get no signal.

I have gameport enabled in m16init. Do I need to do anything else to route midi signals through the gameport?

Thanks

EDIT: I just read the above comments. I also get no MIDI even when slowing my k6+ down to 386 speeds in DOS.