You shouldn't expect this project to work; nor should you run it on real hardware.

Useful addresses and notes

• VIA
  • 0xF00000 to 0xF80000 on the 128k, 512k, Plus and SE
  • doesn't exist on Macintosh Portable? unclear
  • 0x50000000 to 0x50002000 on the SE/30, II, IIx, IIcx, IIfx and IIci
    • On systems with a second VIA, it is located at 0x50002000 to 0x50004000
• IWM ("Integrated Woz Machine" floppy controller)
  • 0xE00000 to 0xD00000 on the 128k, 512k, Plus and SE
  • Other models have a SWIM floppy controller from 0x50016000 to 0x50018000, except the Macintosh Portable and IIfx which have SWIMs at 0xF60000 and 0x50012000 respectively
• See page 42 of the Guide to the Macintosh Family Hardware, 2nd Edition for more info.

It looks like supporting the Portable and IIfx will likely be more complex. Support can initially be focused on the 128k/512k/Plus/SE with support for the Macintosh II-line coming later.