exxos's Atari, Amiga & retro forum

LarryL wrote: 27 Jun 2024 13:21 Still not sure if I can work without A14 & A15 to reuse these inputs for IDE port selection and enable/disable…

For every address line you ignore, you get additional "mirrors" of your IDE adapter in the address space. Whether this is problematic or not depends on if there already is other hardware at the mirror address. In particular, if you don't decode A14 and A15 in an IDE adapter, you get mirrors at 0xF040xx, 0xF080xx, 0xF0C0xx. That might be okay, unless you have some third-party HW that resides at one of these addresses.

czietz wrote: 27 Jun 2024 17:08 For every address line you ignore, you get additional "mirrors" of your IDE adapter in the address space. Whether this is problematic or not depends on if there already is other hardware at the mirror address. In particular, if you don't decode A14 and A15 in an IDE adapter, you get mirrors at 0xF040xx, 0xF080xx, 0xF0C0xx. That might be okay, unless you have some third-party HW that resides at one of these addresses.

thanks, understood...

I doubt that there is "somewhere" an overview, what 3rd party HW is using which addresses? :mrgreen:
OK, I will try some searching...

maybe switching to a different CPLD and do full address decoding would be best...