Changes

After installing AMSDOS, HIRAM is usually A6FBh. Some machine code programs do reinstall AMSDOS with incoming HIRAM=B0FFh (deallocating the BASIC region), the resulting HIRAM is then ABFBh.

Concerning the BIOS, LORAM/HIRAM "exist" only while installing expansion ROMs via KL_ROM_WALK and KL_INIT_BACK, as well as after starting something with MC_BOOT_PROGRAM or MC_START_PROGRAM. Thereafter, the BIOS forgets these values (the BASIC does store hi/lo somewhere in the BASIC area, the BIOS does store hi, too, but there's no BIOS function to retrieve them).