I see from logic of Trump card PAL 1 (1v4) access to WD1772 is assigned to area $1C000-$1DFFF. Has anyone any info of further decode in this area? More to the point; would incidental access to $1C060 & $1C064 (ie. for proof of GC/SGC existence) potentially cause upset to FLP hardware/driver?
Addresses assigned to WD1772 registers/drive select can be extracted from driver source, but I can't be sure of potential incomplete decode.
Edit : Nope
$1C000-$1DFFF = WD1772 chip select (A1-A0 = A1-A0)
$1E000-$1FFFF = 74F175 clock (D3-D0 = side/motor/ds1/ds2)
Lots of incomplete addressing.