scholarly journals 2-1 LTO Tape Drive Technology

2016 ◽  
Vol 70 (5) ◽  
pp. 377-381
Author(s):  
Shinobu Fujihara
Keyword(s):  
Tape Drive

Routine Digital Processing of Microscope Images

1990 ◽  
Vol 48 (1) ◽  
pp. 550-551
Author(s):  
E. Wisse ◽  
A. Geerts ◽  
R.B. De Zanger
Keyword(s):  
Operating System ◽  
Digital Processing ◽  
Hard Disks ◽  
The Sun ◽  
Tape Drive ◽  
High Definition ◽  
Fluorescent Microscope ◽  
Microscope Images ◽  
Helical Scan ◽  
Ethernet Connection

The slowscan and TV signal of the Philips SEM 505 and the signal of a TV camera attached to a Leitz fluorescent microscope, were digitized by the data acquisition processor of a Masscomp 5520S computer, which is based on a 16.7 MHz 68020 CPU with 10 Mb RAM memory, a graphics processor with two frame buffers for images with 8 bit / 256 grey values, a high definition (HD) monitor (910 × 1150), two hard disks (70 and 663 Mb) and a 60 Mb tape drive. The system is equipped with Imaging Technology video digitizing boards: analog I/O, an ALU, and two memory mapped frame buffers for TV images of the IP 512 series. The Masscomp computer has an ethernet connection to other computers, such as a Vax PDP 11/785, and a Sun 368i with a 327 Mb hard disk and a SCSI interface to an Exabyte 2.3 Gb helical scan tape drive. The operating system for these computers is based on different versions of Unix, such as RTU 4.1 (including NFS) on the acquisition computer, bsd 4.3 for the Vax, and Sun OS 4.0.1 for the Sun (with NFS).

Head-Wear Measurements by Autoradiography of the Worn Magnetic Tapes

1986 ◽  
Vol 108 (1) ◽  
pp. 22-28 ◽  
Author(s):  
B. Bhushan ◽  
G. W. Nelson ◽  
M. E. Wacks
Keyword(s):  
Magnetic Tape ◽  
Wear Debris ◽  
Zinc Ferrite ◽  
Tape Drive ◽  
Average Amount ◽  
Nickel Zinc ◽  
Total Head ◽  
Drive Component

The transfer of wear debris of a nickel-zinc ferrite head to a magnetic tape was measured by autoradiography of the tape after it was worn against the irradiated ferrite head. Ferrite deposits on the tape were observed only after 5000 passes. Dots or specks on the autoradiograph of the tapes of about 200 micrometers in diameter, caused by particles of ferrite about 1 μm in diameter and mass of about 10−11 g, were measured. The average amount of ferrite deposited on the tape after 20,000 passes was about 0.6 nanogram per square centimeter; some areas showed uniform deposits of ferrite concentration of 10–20 ng/cm2. Based on our estimates of total head wear, only a small fraction (about 0.6 percent) of the total ferrite wear debris was transferred to the tape, about 0.2 percent was transferred to the tape-drive component surfaces, and the rest, we conclude, was airborne.

How Colossus was Built and Operated—One of its Engineers Reveals its Secrets

Colossus ◽  
2006 ◽  
Author(s):  
Harry Fensom
Keyword(s):  
Tape Drive ◽  
Wrong Answer ◽  
Photoelectric Equipment ◽  
Tape Reader ◽  
Frequency Modulator ◽  
Working Together ◽  
Exclusive Or ◽  
Digital Or

Flowers’ team, which included me, became involved with the design of the logic units of Newman’s proposed machine after Morrell’s Telegraph Group, which had been assigned the job, got into difficulties. For modulo-2 addition (‘exclusive-or’, or XOR) Morrell was proposing to use a type of frequency-modulator employed for voice-frequency telegraph signals. This might have been all right for adding only two signals, but it was useless for adding many signals, because the device was analogue in nature (i.e. not digital or discrete, but using continuously variable voltages). The small variations added up, with the result that the device often produced a wrong answer. After some clever work by Gil Hayward, it just about worked for the number of additions that were required. The Heath Robinson’s ‘bedstead’, containing the tape drive and the photoelectric tape-reader, was designed and built at Dollis Hill. Our people Eric Speight and Arnold Lynch had very recently used photoelectric cells to do what was required. Fighter Command had asked Dollis Hill for a fast means of recording the telegraphic signals from their aircraft observers. Speight and Lynch, working together with Morrell’s group, had designed some photoelectric equipment that would record these signals directly from the telegraphic punched tape. The device they built, called the ‘Auto-Teller’, was never in fact used, but this photoelectric technology formed the basis for the bedstead. When we finished our part of Newman’s machine at Dollis Hill I moved to Bletchley Park, and Alan Bruce from TRE accompanied their part of the machine, the counter and display rack. The Heath Robinson was installed in the wooden Hut 11—the Newmanry. I was privileged to be one of those present at the Heath’s inauguration before the VIPs—and I can confirm that smoke did rise from it at switch-on. I was able to deal with this. A large resistor had overloaded, which I bypassed, and we carried on. (The machine never did catch fire, on this or any other occasion, but as mentioned in Chapter 13, we had a benzene fire in our workshop, at a much later date, and this may have contributed to the erroneous stories of Heath Robinson catching fire.)

Study of Light Weight Turbine Transmission Systems

1976 ◽  
Author(s):  
D. J. Fessett
Keyword(s):  
Gas Turbines ◽  
State Of The Art ◽  
Chain Drive ◽  
Tape Drive ◽  
Hydraulic Power ◽  
Transmission Systems ◽  
Determining Factors ◽  
Technical Risks ◽  
The Right ◽  
Marine Vessels

Several transmission systems that are applicable to advanced marine vessels were investigated to determine if drives other than right-angle gearboxes would be practical in transmitting 50,000 (37.3 NW) hp from dual gas turbines downward through a vertical distance of 20 (6.10 m) ft to a propeller drive shaft. These systems included: hydraulic power, chain drive, steel tape drive, and a slider crank drive. Results of this survey indicated the right-angle bevel gear drive was the optimum system considering our present state-of-the-art. Further investigation was performed to optimize turbine and gearbox arrangement using weight, reliability, efficiency, serviceability, technical risks, and relative cost as the determining factors.

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