Probably will work if you only write to the MPU port, i.e. play MIDI. If you want to read from the MPU you may get in trouble. I may be wrong though.

No. It WILL result in a lock-up.
It is not like having two OPL3 cards playing at the same FM port happily.

On a footnote,
you can experiment with a purely PnP system where only the cards/ports you actually use are initialized. This way you might be able to rotate 300h or 330h amongst the cards.

A lot of games are indeed hard-coded for port 330. Likely not the advice you want to hear, but when you want to use a range of MIDI devices, it makes sense to get the external versions. They can be daisy chained or connected with a MIDI hub.

Thank you. I guess I'm not going to try myself.

As port number in both cases is adjusted by the set of two jumpers, I thought I could install some external switch that would allow to assign 300H port addres to either card.

But then, after some further testing I will put Ensoniq in 386 system I am planning to build, alongside with SB PRO 2. Ensoniq is not really period correct and later I will replace it with some MT-32 with 8 Music Quest interface.

In my current 5x86 build I will keep GUS, SW60XG and another SB PRO 2 or Yamaha Audician for OPL3 sound.

Remember, the only resource that can overlap amongst cards is DMA. Even in this case, when 2 or more cards are set to the same DMA, only One card is allowed to use it. We are speaking about DOS and classic ISA cards.

So for example, you can have 2 Sound Blasters in a system, one is PnP:
CT1330:
A220 I7 D1 T2
CT2940:
A240 I5 D1 H5 T6

but the two cards are never accessed simultaneously by any game which uses DMA 1 or you will get a crash.
You should not configure two non-PnP cards to the same resources, of course.

The external jumper switcher you are planning will only work when the system is powered down, not very convenient, unfortunately. Same case as an external FSB switch which freezes the computer in real mode.

Jolaes76 wrote:

No. It WILL result in a lock-up. It is not like having two OPL3 cards playing at the same FM port happily. […]
Show full quote

No. It WILL result in a lock-up.
It is not like having two OPL3 cards playing at the same FM port happily.

On a footnote,
you can experiment with a purely PnP system where only the cards/ports you actually use are initialized. This way you might be able to rotate 300h or 330h amongst the cards.

This may be an interesting update:

As the feedback I received in this topis was quite consequent, I did not attempt to run both cards at the same port (330h). Until today.

I have put two soundcards into my ASUS 386-33/64K based system - Yamaha SW60XG and Ensoniq Soundscape II. Both hard-set to 330h. I started the computer, initialized Ensoniq card and it looks like the both cards can work simultaneously and this does not cause any hangs or crashes.

I tried with Tyrian2000 so far and I'm getting output from both cards at the same time!

Interesting! I was cock-sure about this being impossible... but it seems if you drop Creative cards from the equation it works. Maybe there are other successful card combinations...?
I recon the biggest score would be to make a real MPU-401 interface (like an IPC-T) coexist with an UART MPU-401 at the same address.

With Ensoniq you seem to be quite close to true MPU-401, as it is said to emulate intelligent mode.

Unfortunately I cannot test any MPU-401 interface, as I don't have any external sound module. But my intuition tells me this should work.

Jolaes76 wrote:

Interesting! I was cock-sure about this being impossible... but it seems if you drop Creative cards from the equation it works. Maybe there are other successful card combinations...?
I recon the biggest score would be to make a real MPU-401 interface (like an IPC-T) coexist with an UART MPU-401 at the same address.

I have MPU-IPC-T, never tried this though (sharing same port). Come to think of it, I have yet to use it together with a Yamaha XG card.

Hi all. I tried above in my system:
Two cards at P330. One lapc I, one Aztecs 2320 pnp.

Outcome:
It really works. Once.
I can start a game like dune 2 and get GM via the Aztech MIDI port. All works great. But after quitting the game the system hangs. In my case this means I have to continuously press Num button. After each pressing the system does again something for a second. E.g. I have to press 20x Num to get NC loaded. Warm reboot keeps the symptom. Just cold reset helps OR reconfiguring the PnP card to another MIDI port (but this needs 40x Num lock press until executed).

I tried to solve issue with setting the pnp to 340 and then using softmpu with port forwarding. But then I get no MIDI output at all strangely.

Just FYi

PS: interestingly it doesn’t work if I want to hear the lapc I at all. Seems like the system only sends it to one of the 330 Address. Don’t know why it always is the aztech i don’t know. Maybe card ID, slot number or something.