EN 29661-1991 信息处理.在12.7mm(0.5in)盒式磁带上进行数据交换.每毫米18磁道、1491数据字节(每英寸37871数据字节)(ISO 9661-88)
Information processing; data interchange on 12.7 mm (0.5 in) magnetic tape cartridges - 18 tracks, 491 data bytes per millimetre (37871 data bytes per inch) (ISO 9661 - 1st edition, 1988)