BE76 2 Pointer to 512-byte Sector I/O Buffer (A9B0h) (CPM:AEF8h)
BE78 1 Flag Enable/Disable Error Messages
BE79 1 Reserved, CPC+: 00h=Normal, FFh=Enable Keyboard Scanning during I/O
BE7A 1 Reserved, CPC+: 00h=No Disc (464+), FFh=Disc (6128+)
BE7B 2 Reserved