  We revisit the IEEE 1394 high-performance serial bus ("FireWire"), which
became a success story in formal methods after three PhD students, by using
process algebra and model checking, detected a deadlock error in this IEEE
standard. We present four formal models for the asynchronous mode of the Link
Layer of IEEE 1394: the original model in muCRL, a simplified model in mCRL2, a
revised model in LOTOS, and a novel model in LNT.
