IO$_CREATE
IO$_ACCESS IO$_DEACCESS IO$_MODIFY IO$_DELETE IO$_ACPCONTROL  | P1 —
FIB descriptor address P2 — file name string address P3 — result string length address P4 —
result string descriptor address P5 — attribute
list address  | IO$M_CREATE[3] IO$M_ACCESS[3]  IO$M_DELETE[4]  IO$M_DMOUNT[5]  |