Editing IBM 729 (section)

==Data format==
The tape had [[IBM 7-track|seven parallel tracks]], six for data and one to maintain [[parity bit|parity]]. Tapes with character data (BCD) were recorded in even parity. Binary tapes used odd parity (709 manual, p.&nbsp;20). Aluminum strips were glued several feet from the ends of the tape to serve as physical beginning and end of tape markers. [[Write protection]] was provided by a removable plastic ring in the back of the tape reel. A 3/4&nbsp;inch gap between records allowed the mechanism enough time to stop the tape. Initial tape speed was 75&nbsp;inches per second (2.95&nbsp;m/s) and recording density was 200 characters per inch, giving a payload transfer speed of 90&nbsp;kbit/s (105&nbsp;kbit/s including parity bits). Later 729 models supported 556 and 800 characters/inch and 112.5 in/s (payload transfer rates up to 540&nbsp;kbit/s; raw transfer rates up to 630&nbsp;kbit/s). At 200 characters per inch, a single 2400-foot tape could store the equivalent of some 50,000 [[punched card]]s (about 4,000,000 six-bit bytes, a data quantity equivalent to three million octets).

The 729 series was superseded by [[9-track tape]] drives introduced with the [[IBM System/360]].