Bus Error testing results (word access):
(Mega ST4, likely with IMP chipset)

$FF800E - $FF8200
$FF820E - $FF8240
$FF8280 - $FF8604
$FF860E - $FF8800
$FF8900 - $FF8A00
$FF8A40 - $FFFA00
$FFFA40 - $FFFC00
$FFFE00 - $FFFFFE

EOF!
