They are fully decoded, no other ports are used at this time.
Thanks Duke.
However, sad news are there.
When using the M4 with the 6128plus, there is a bug. It does crash FutureOS.
What's the problem?
On the 6128plus the ASIC needs to be fed with 17 bytes to activate its features. After that the command:
ld bc,&7f8b:out (c),c
will activate the memory mapped I/O between &4000-&7FFF.
On the M4 card this OUT does in addition switch off the upper ROM! Which causes a crash in some cases (FutureOS f.e.). But this OUT is NOT supposed to alter the ROM/RAM status.
How to fix the problem?
I'm not a hardware person, but with other ROM expansions there are not problems.
An idea would be that the M4 card shall ignore commands like:
OUT &7Fxx,&B8 and
OUT &7Fxx,&A0 (they are used on 6128plus for switching memory mapped I/O on and off).
@Duke : Hope you can help with this issue. It would be greatly appreciated.