The IBM 7330 Magnetic Tape Unit was IBM's low-cost tape mass storage system through the 1960s. Part of the IBM 7 track family of tape units, it was used mostly on 1400 series computers and the IBM 7040/7044. The 7330 used

magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic ...

up to long wound on reels up to diameter.

Data format

The tape had seven parallel tracks, six for data and one for parity. Tapes with character data (BCD) were recorded in even parity. Binary tapes used odd parity. (709 manual p. 20) Aluminum strips were glued several feet from the ends of the tape to serve as beginning and end of tape markers. Write protection was provided by a removable plastic ring in the back of the tape reel. A ¾ inch gap between records allowed the mechanism time to stop the tape. At 200 characters per inch, a single 2,400-foot tape could store the equivalent of some 50,000

punched card A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...

s (about 4,000,000 six-bit bytes). Low speed (36 in/s) dual density (200, 556).

External links

IBM Magnetic Tape Equipment manuals (in PDF format)
on bitsavers.org 7330 7330 Tape 7330 {{compu-storage-stub