Next: READBACK TESTS Up: Tape Management Previous: TAPE LENGTHS and PASS Contents . ... The Mark III and VLBA systems make longitudinal recordings using many heads, all mounted on a head stack. ... Modes with 2 heads are MarkIV only. ... Bit rate: 64 Mbps 128 Mbps 256 Mbps 17600 All/High 20:32:00 10:16:00 5:08:00 17600 VLBA/Low 12:19:12 6:09:36 3:04:48 17600 Mark III/IV/Low 12:09:52 6:04:56 3:02:28 8800 VLBA/Low 6:09:36 3:04:48 1:32:24 8800 Mark III/IV/Low 6:04:56 3:02:28 1:31:14 2 Pass/head pos. ...

metrologia The leap second: its history and possible future R. A. Nelson, D. D. McCarthy , S. Malys, J. Levine, B. Guinot, H. F. Fliegel , R. L. Beard and T. R. Bartholome w Abstract. This paper reviews the theoretica l motivatio n for the leap second in the context of the historica l evolutio n of time measurement . Th e periodic insertio n of a leap second step into th e scale of Coordinate d Universal Time (UTC) necessitates frequent changes in comple x timekeepin g systems an d is currentl y th e