That's a write-enable ring, not a write protect ring... The specs are at http://bitsavers.trailing-edge.com/pdf/ibm/magtape/A32-0006-1_Tape_Specifications_for_IBM_One-Half_Inch_Tape_Drives_at_556_800_BPI_and_3200_FCI_Jul69.pdf Lawrie (talk) 00:45, 15 December 2018 (UTC)
