Editing IBM System/360 (section)

===Tape drives===
[[File:IBM System 360 tape drives.jpg|thumb|IBM 2401 tape drives]]

The 2400-series of 1/2" magnetic tape units consisted of the 2401 and 2402 Models 1-6 Magnetic Tape Units, the 2403 Models 1-6 Magnetic Tape Unit and Control, the 2404 Models 1-3 Magnetic Tape Unit and Control, and the 2803/2804 Models 1 and 2 Tape Control Units.<ref>{{cite book| url=http://bitsavers.org/pdf/ibm/2400/A22-6862-4_2400_Series_Magnetic_Tape_Units_OEM.pdf |title=IBM 2400-Series Magnetic Tape Units Original Equipment Manufacturers' Information |edition=fifth}}</ref> The later 2415 Magnetic Tape Unit and Control, introduced in 1967 contained two, four, or six tape drives and a control in a single unit, and was slower and cheaper.<ref>{{cite web |url=http://ed-thelen.org/comp-hist/IBM-ProdAnn/2415.pdf |title=IBM 2415 Magnetic Tape Unit and Control for System/360}}</ref> The 2415 drives and control were not marketed separately.<ref>{{cite book |url=http://bitsavers.org/pdf/ibm/2400/GA22-6862-6_2400-Series_OEM_Nov70.pdf |title=IBM 2400-Series Magnetic Tape Units Original Equipment Manufacturers' Information |date=November 1970 |edition=seventh}}</ref> With System/360, IBM switched from [[IBM 7-track]] to [[9-track tape]] format. Some 2400-series drives could be purchased that read and wrote 7-track tapes for compatibility with the older [[IBM 729]] tape drives. In 1968, the IBM 2420 tape system was released, offering much higher data rates, self-threading tape operation and 1600bpi packing density.<ref>{{cite book |url=http://bitsavers.org/pdf/ibm/2420/A32-0004-0_2420_Model_7_OEM_Oct68.pdf |title=IBM 2420 Model 7 Magnetic Tape Unit Original Equipment Manufacturers' Information |date=October 1968}}</ref> It remained in the product line until 1979.<ref>{{cite web |url=https://www.ibm.com/ibm/history/exhibits/storage/storage_2420.html |title=IBM 2420 magnetic tape unit|website=[[IBM]] |date=23 January 2003 }}</ref>