OK, so i've made Heart of China work by still using the Willy Beamish driver but i instead patched the 001, 003 and 101 PAT files by replacing the code inside with the Heart of China equivalents. It was Hex Editing work mainly but it was easy enough and the first impression is that it is working perfectly. Willy Beamish seems to have a driver for the Pro Audio Spectrum inside its SX.OVL file, but i haven't tried if Heart of China can use it as an added benefit of my hack.

OK, i managed to actually do this properly by extracting proper SX.OVL files for the various games, extract and unpack them patch the Tandy driver and then i put a compressor together with AI assistance to repack the file. Then was just a matter of applying the patched compressed driver to the OVL sound files for each game and that was it.

Only one that I couldn't figure out yet is Stellar 7 RES format. It seems like the information out there about it is slightly wrong or incomplete.

Fantastic work! Much respect.

I managed to patch Stellar 7, for Tandy using a 2 byte port and also managed to make the Sound Blaster driver work with IRQ 5 and IRQ 7 in detriment of IRQ 3. I think it's a reasonable trade off.

Stellar 7 RES file with Tandy sound on port 1E0h and IRQ 5 support for Sound Blaster:

Back up your original STELLAR.RES, just in case. This is for the floppy version, BTW...

Edit: Too bad NRS isn't around anymore, this would be nice with a MTBLAST driver of sorts.

By using same NRS brilliant logic i was able to patch SC1 MTPRO.DRV, that allows to use a MT-32 synth plus the digital capabilities of a Pro Audio Spectrum. The patched file, which is bigger, than the original MTPRO.DRV has appended code right at the end probing IRQ and DMA dynamically by checking INT 2Fh AX=BC04h. Then it's just the matter of patching correct memory locations after some needed tweaks. This allows any PAS IRQ/DMA configuration to work, instead of relying on the IRQ 7, DMA 1 hardcoded values.

I renamed the file to MTPAS.DRV, allowing to keep the original.

EDIT: Tested with LSL5, PQ3, LSL1 VGA remake, SQ1 VGA remake. I wanna bet it also works with other SCI1 games i'm not remembering at the moment