Now that we emulate even exotic hardware from ancient times, i'd like to tackle long standing bugs
1. all hard disk boot loaders i tried crash our emulation (including, but not limited to
latest WUTIL 3.2.x and DSKPREP).
It is possible to generate boot diskettes with DSKPREP for both MS-DOS and CP/M, yet neither 'autoboot' (from BIOS) nor a manual boot (W key) works correctly.
2. the ZFLIP flag or another Z80 register is wrong after CTRL/Setup (= standard method to warm boot the Rainbow)
I got some clues why 1. happens, and will report later
