9-track tape is a format for magnetic-tape data storage, introduced with the IBM System/360 in 1964. The 1⁄2 inch (12.7 mm) wide magnetic tape media and reels have the same size as the earlier IBM 7-track format it replaced, but the new format has eight data tracks and one parity track for a total of nine parallel tracks. Data is stored as 8-bit characters, spanning the full width of the tape. Various recording methods have been employed during its lifetime as tape speed and data density increased, including PE, GCR, and NRZI. Tapes come in various sizes up to 3,600 feet (1,100 m) in length.
IBM 2401 System/360 tape drives that introduced the 9-track format
Full-size reel of 9-track tape
9-track tape drive used with DEC minicomputers
Inside a 9-track tape drive. The vacuum columns are the two gray rectangles on the left.
Magnetic-tape data storage
Magnetic-tape data storage is a system for storing digital information on magnetic tape using digital recording.
10+1⁄2-inch (270 mm) diameter reel of 9-track tape
Quarter-inch cartridges
An IBM 3590 data cartridge can hold up to 10GiB uncompressed.
IBM 729V