FBF6h 765 FDC (Vortex,ext) Status Register (Read)
FBF7h 765 FDC (Vortex,ext) Data Register (R/W)
FA7Eh Floppy Motor On/Off Flipflop (nearly same as normal, bit precise)
(The Special addresses are mentioned in the manual
for the Vortex -X drives) (but apparently they are referring