(NRZI) A recordiNg method used for 9-track {magNetic tapes} (200 aNd 800 BPI) where a zero is represeNted by a chaNge iN the sigNal aNd a oNe by No chaNge. NRZI is also used exteNsively iNSDLC commuNicatioNs. VTAM has a parameter NRZI=YES|NO. Compare Phase ENcoded, GCR. (1999-01-11)