James Attfield wrote:
FYI the ROM on the 'FDC flips in and out the entire top 32K bank.
I just double checked the schematics and this is not correct.
The 16FDC feeds address lines 15-12 through a 74ls30 to do a
specific decode for a 4K address range, normally set to $C000-$CFFF.
If the high four address bits do not match, the card will not
respond.
Bill S.