IBM 726

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The IBM 726 dual magnetic tape reader/recorder for the IBM 701 was announced on May 21, 1952. Unlike later IBM 7 track drives, the 726 could read backwards as well as forwards.

The tape had seven parallel tracks, six for data and one to maintain parity. Tapes with character data (BCD) were recorded in even parity. Binary tapes used odd parity. Aluminum strips were glued several feet from the ends of the tape to serve as logical beginning and end of tape markers. Write protection was provided by a removable plastic ring in the back of the tape reel.

tracks	6 Data, 1 parity
chars/inch	100 Chars/inch
end of record gap	1 Inch - 100 chars - 16.67 words
Start time	10 Millisec
Stop time	10 Millisec
Width of tape	1/2 Inches
Length of reel	1,400 Feet
Composition	cellulose acetate base

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• IBM 726 Magnetic tape reader/recorder

view • talk • edit	Magnetic tape data storage formats
	Linear	Helical-Scan
Three Quarter Inch (~19 mm)	LINCtape (1962) - DECtape (1963)	Sony DIR (19xx) - Ampex DST (1992)
Half Inch (12.65 mm)	UNISERVO (1951) - IBM 7 Track (1952) - 9 Track (1964) - IBM 3480 (1984) - DLT (1984) - IBM 3590 (1995) - T9840 (1998) - T9940 (2000) - LTO Ultrium (2000) - T10000 (2006)	Redwood SD-3 (1995) - DTF (19xx) - SAIT (2003)
Eight Millimeter (8 mm)	Travan (1995) - IBM 3570 MP (1997)	Data8 (1987) - Mammoth (1994) - AIT (1996) - VXA (1999)
Quarter Inch (6.35 mm)	QIC (1972) - SLR (1986) - Ditto (1992)
Eighth Inch (3.81 mm)	KC Standard, Compact Cassette (1975) - DC100 (1976) - Datassette (1977) - DECtapeII (1979)	DDS/DAT (1989)
Stringy (1.58 - 1.9 mm)	Exatron Stringy Floppy (1979) - ZX Microdrive (1983) - Rotronics Wafadrive (1984)