Multichannel Write and GMR Heads for Over 1 TB Tape System

This paper reports on the structure and performance of multichannel write and giant magnetoresistive (GMR) heads for a helical-scan tape system. The four-channel write head was fabricated with four layers stacked and shifted by a track pitch. The eight-channel read head was also stacked four layers, each of which has two spin-valve elements. The write head and read head were assembled into a commercial drive. Four channels are written in one revolution without a guard band and each of the eight channels is read, in half of the track pitch. The feasibility of a recording density over 4.3 Gb/in² was established, which would make possible a tape system of over 1 TB using an 8 mm cassette