Hi!
I like TK Chia's idea that DOS/16M tried to access the keyboard controller to change A20: It would probably stop doing that when HIMEM and/or EMM386 are loaded, but having a DPMI loaded can be even more convincing. Same for DOS4GW: If A20 control is already provided by something else, or protected mode is already being used, it is less likely to try to change the A20 itself. For PC, the BIOS tends to trap I/O to the controller so even USB keyboards can behave like real ones, but your iMac / rEFInd / CSM probably do not do this. You can still try whether one of the CTMOUSE versions is able to use the mouse via PS/2 BIOS calls with some suitable command line options. May depend on the model. > VGA + VESA (graphics) works. It's discovered VESA 3.0 with LFB Quite nice :-) > Sound card related experiments are still in front of me Expect only a few modern media players like MPXPLAY to support AC97 or HDA at all. If you want soundblaster compatibility, you would have to use emulators. There seems to be a DOSBOX-X version which can run inside DOS which might help with that, but the normal way would be to use Windows or Linux with DOSEMU2 ;-) Regards, Eric PS: No idea whether your CSM is rEFInd provided, Apple provided or from somewhere else. If you would know, you could simply read docs instead of testing it's features. Maybe some strings at f000:0 to f000:ffff give answers? _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user