"address","size","name","r/w","description"
"0018","1","alternate_status","R",
"0018","1","device_control","W",
"0080","2","data","RW",
"0084","1","error","R",
"0084","1","features","W",
"0088","1","interrupt_reason","R",
"0088","1","sector_count","W",
"008C","1","sector_number","RW",
"0090","1","byte_control_low","RW",
"0094","1","byte_control_high","RW",
"0098","1","drive_select","RW",
"009C","1","status","R",
"009C","1","command","W",