NeoG_ wrote on Today, 04:48:

Kahenraz wrote on Today, 03:24:

If you swap an ES1868 with an ES1869, will it still gain full duplex in this compatibility mode?

Based on what LS10999 is saying, if you put an ES1869 in place of an ES1868, it will still require ES1868 drivers. If ES1868 drivers are installed, the full duplex feature is not available.

I think for full duplex you need to check the PnP config to see if the card is configured to use a second, different DMA channel than the one used for playback. Assuming playback is done on DMA1 which is the usual Sound Blaster default, the card can use DMA0 for recording.

EDIT: Further reading of the datasheets of both ES1868 and ES1869 suggest there weren't any significant difference regarding full-duplex operation between them. For both ES1868 and ES1869:
- Only mono is supported -- the left channel is used for recording while the right is used for playback.
- Two separate DMA channels needed.
- Playback and recording sample rate must be identical (e.g. 22050 Hz). A separate IRQ can be assigned for recording but is optional because of this.

Terratec Gold 16/96 uses ES1868 and it is one of my top three favorite hassle free MS-DOS sound cards.