That's a good point about the Classic's built-in OS. I actually have a Classic here, but I never tried it. I wonder how it's implemented, and at what level? Like, does the phantom disk appear as a floppy, or a SCSI device? Does it prevent a real floppy/SCSI drive from being used at that address or drive? Does it install a new device driver?
Another interesting discovery: Benjamin Herrenschmidt has already created a mostly-working Mac Plus core for the Amiga Minimig, which is pretty similar to what I'm doing. He invited me to borrow whatever might be useful. Code is at http://git.ozlabs.org/?p=minimigmac.git I’ve been looking at several of his modules to make sure his interpretation of the docs matches mine. I want to avoid outright copying of his design modules though, since then I wouldn’t learn anything, and puzzling things out for myself is most of the fun.
Another interesting discovery: Benjamin Herrenschmidt has already created a mostly-working Mac Plus core for the Amiga Minimig, which is pretty similar to what I'm doing. He invited me to borrow whatever might be useful. Code is at http://git.ozlabs.org/?p=minimigmac.git I’ve been looking at several of his modules to make sure his interpretation of the docs matches mine. I want to avoid outright copying of his design modules though, since then I wouldn’t learn anything, and puzzling things out for myself is most of the fun.