Schematic of the PS1 needed to answer the question.

https://ps1stuff.wordpress.com/documentation/

Here is some documentation.

It's possible - most of the pins directly match the ISA bus.

The exceptions:
- AUDOUT - your audio output
- MODIN, MODOUT - likely for the modem
- CLK - needs to be figured out what it needs, 1MHz or 14.3MHz or something else - audio generator uses 1 microsecond clock but maybe has a pre-divider

You may start with something like that:
http://www.futurlec.com/Protoboards.shtml -> ISA Bus Computer Board
and the opposing connector for the audio card.

Your other problem will be the software support.

Clock is 4mhz

So you'll also need a crystal oscillator plus a blocking capacitor, like this: http://www.ebay.de/itm/4MHz-Xtal-Quartz-Cryst … l4AAOSwU9xUR5U8

Wait a minute, here they write that CLK is 10MHz:

I dunno. Jmk (the guy who made ps1 audiocard dosbox patch) said he read the technical sheet and he found evidence that the sound chip is fed by a 4 Mhz clock.

This should answer your questions : http://nerdlypleasures.blogspot.com/2015/10/t … sound-chip.html

Nice article Great hierophant! The card in the pics is indeed my card, taken from a ps1 2121 model (I don't own the rest of the pc anymore).