The HITACHI D-5500 was introduced in 1979 and it was one of those Super decks that was competing for supremacy. It was a sophisticated 2 motor deck featuring Hitachi's own Unitorque Direct Drive motor (0.028% WRMS wow and flutter) and their own "Close Gap" R&P heads in a 3 head configuration. The highlight of this deck was the ATRS (Automatic Tape Response System). The ATRS brain is a sophisticated microcomputer that's built into the Hitachi D-5500 Cassette Deck. Because there were hundreds of different tapes on the market, ATRS was designed to match bias and EQ settings to the precise characteristics of each one you use. Press the Test button while in record and in 20 seconds ATRS carries out six calibration functions. It also has three individual memories for the test results of the three tapes you use most frequently. For the ultimate in user comfort interface the Hitachi D-5500 features a full IC logic detachable control block that doubles as a wireless infrared remote unit. Soon after the release of the D-5500 it was introduced the D-5500M that added Metal tape compatibility. Both models were available in silver and black, the worldwide model was sold as HITACHI while the Japan domestic model was sold as Lo-D.