Rudy Biesma (the author of the +DivIDE firmware) has so far commented:
Can't get floppy working (yet), reason Floppy Disk Controller uses port 227, which happens to be the control port for DivIDE (Plus).. Trying to work around it but the workings of port 23 is not exactly as the manual says. The biggest problem is that some FDC commands set MAPRAM mode (because of equal port address). When I soft reset DivIDE Plus it doesn't always work OK.
and today's update:
The problem with the Floppy Disk Controller remains, I've tried some but it seems the soft reset of the DivIDE doesn't do what I expect... The best solution would be the replacement of the PAL chip (not the EPROM) in the +D in order to remap the FDC's I/O ports. I will try that the coming period but during the holiday season, which starts coming week, I have to work close to 7 days a week.
The printer port doesn't seem to have conflicts, I tried from BASIC doing some OUT's and the printer responds OK. So the printer routines could be added fairly easy (I probably 'borrow' the complete +D code).
I've redesigned (not fully implemented yet) the way the system accesses d1 and d2. It will see the d1 and d2 as logical drives, pointers to a device driver so it can use floppy, IDE or whatever there is a driver for (I have ideas about the latter but don't now if I will be writing those drivers). GDOS had only to cope with floppy so the code is a bit dirty, meaning the device independent and the device depended code isn't separated. Because +DivIDE was never meant to handle another device it is also quick and dirty. Patching the code now gives problems later when .TAP support has to be added. 'Some more work today keeps the headache tomorrow at bay'.
To be continued.