Device
  asynchronous IORequests, 449
  closing, 450
  commands, 448
  device base address pointer, 452
  device names, 447
  device specific command prefixes, 448
  devices with functions, 452
  error checking, 450
  error indications, 450
  gracefully exiting, 451
  opening, 447
  passing IORequests, 447
  problems, 917
  romtag, 444
  sharing library bases, 467
  standard Exec commands, 448
  synchronous IORequests, 449
  task structure fields for, 466