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Hardware / Re: Two Sound Cards on OS/2-eCS
« on: March 05, 2014, 08:18:25 pm »Thanks for the replies.
Sorry, I didn't actually mean two "cards" , I actually mean two "chipsets", I just noticed I was not clear. But I understand more about it now. But I think we are missing some tool to administrate the sound cards a Windows has.... but I think we need first to have more audio drivers
I also want to test the test USBAudio drivers, that's why I try to figure it out how to mnage two chipsets on OS/2-eCS. But I still can not make the USB audio devices that I have to work yet.
1) There IS a tool to administer sound cards in OS/2. You will find it as "Multimedia Configuration" in the "System Configuration" folder.
2) Multiple sound cards: this is a bit involved. When you install a sound driver, apart from other things, the MMPM2.INI file in the \MMOS2 folder will be updated. That file creates sound devices with names as Waveaudio01and associates these devices with the real device driver name like say USBAUD1$ and therefore with a real device driver.
If you had more than 1 of the very same sound card there is a logic to assign device driver names, the first one would be USBAUD1$, the next one would be USBAUD2$. Again, each device driver name is associated with a distinct device name: USBAUD1$ -> Waveaudio01, USBAUD2$-> Waveaudio02 etc.
The device names are subsequently used by applications and even the REXX MMPM API to say play a sound file on a specific sound device. For applications there exist API calls to query what devices (device names) exist in a system, an application can therefore build up a choice list to allow the user to pick a specific device.
Just to mention it: USBAUDIO.SYS has a fixed device driver device name of USBAUD1$. In short: you will only be able to load one instance of USBAUDIO.SYS.
However that is no limitation as USBAUDIO.SYS itself can handle multiple USB audio devices. However it will only ever pick the "first" (where "first" would be the one that was found first on the USB bus) USB device to play etc. as there is no selection logic in USBAUDIO.SYS to pick a specific USB audio device. If you unplug a device, USBAUDIO.SYS will pick the next available USB audio device remaining.
Lars