With conflicting or limited information I made a few guesses:
- I've used a WD1770 rather than a WD1773 or an older FDC197x, so relevant bits relate to a potential spin-up sequence rather than a head load, and the side fields in sectors aren't checked; and
- even though I'm an electrical dunce, I could see references to reset and an output to /RES on the schematic so I assumed that the Jasmin boot button causes a processor reset, and since that doesn't achieve much if the Jasmin ROM isn't paged I decided that it probably does that too. I tried defaulting to the Jasmin ROM paged at initial boot, but then the machine wouldn't start at all if a disk is present so I decided that probably doesn't happen.
So:
As a footnote aside, there seems to be a decent overlap here with Atari ST folk so perhaps also worth dropping into the conversation is that Clock Signal now also has a mediocre Atari ST emulation. Not good enough yet for me to dare show my face in the mainstream Atari ST world though. Probably my next item of work there is support for the STX file format, which I've argued elsewhere I think would also be a good fit for the Oric. So it's very possible I'll provide support for that for the Oric soon. In the meantime, you can continue to use standard DSKs or HFEs.
(And, as an aside: the ST uses a WD1772, which is a WD1770 with different stepping rates, so that exposure should also feed back into improving my Oric emulation)