By the way, I've tried setting up my OPTi 82C929-based card again on my P8B75-M and still no success.
The card itself is working okay, as I'm able to set everything up (SB mode, WSS mode, MPU401) on AIMB-865 (ICH5, PCI-ISA) without errors.

Current status of 82C929 (using CS4231A as codec):
- SB mode outright fails complaining about unable to set up SB DSP.
- WSS mode can be set up if using a different port than 530h (e.g. 604h), provided the I/O has been mapped and can be accessible. F40h can be used, and is better because that range can be mapped alongside its configuration ports in a single slot (which resides in F80-F9F range, or F8D-F92 to be precise).
- MPU401 configuration also fails. Not sure if it's because of IRQ2/9 (which is usually claimed by ACPI as ACPI SCI IRQ). On AIMB-865 it's possible to move it to APIC territory by enabling APIC ACPI SCI IRQ, though this will break Win98's ACPI (which is better off disabled anyway).

It's possible to move GPIO registers from 500h elsewhere, such as 480h like RUBY-9719VG2AR, but doing this will not make ports 530/534 accessible for WSS purposes.

Also, WSS ports must be reachable for proper setup of either mode, or the setup will fail citing no compatible codec detected.
Not sure what else might be needed for 82C929 to work in SB mode. All I/O ranges normally used by Sound Blaster (220h, 388h, 330h) should be accessible as my CT2290 already works okay.

I did try using the 82C929 card on RUBY-9719VG2AR and it doesn't work there, either, mainly because of the WSS port issue.

dartfrog wrote on 2025-06-13, 08:11:

I don't want to speak too soon, but spoiler: On the IT8888 front; I've ordered a few pcbs from oshpark. Exciting times.

I also created a BGA to QFP adapter so it's possible to use the IT8888F (QFP footprint) PCI card with the IT8888G (BGA chip)

How's the progress?
Life..?