IEEE Computer Volume 11 Number 12 -- New Products
Original Publication Date: 1978-Dec-01
Included in the Prior Art Database: 2005-Nov-10
Software Patent Institute
True Seaborn: AUTHOR [+3]
THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.
This record contains textual material that is copyright ©; 1978 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society http://www.computer.org/ (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.
edited by Prof. D. A. Michalopoulos California State University, Fullerton edited by Prof. D. A. Michalopoulos California State University, Fullerton
Floppy disk drive solves two-sided wear problems.
ELM, ~IIV ~du~`lpany repottS. A new dual-sided, double-density diskette drive reduces media
wear to far below industry norms, according to Qume Corporation. The company has obtained
an exclusive right to manufacture the drive for the North American and European markets from
Y. E. Data, Japan's leading supplier of floppy disk drives.
The DataTrak 8 diskette drive further ensures data reliability through an increase in signal amplitude and a reduction in bit shift, says Qume.
Media wear caused by head loading "taps" has been a serious problem in applying two-sided floppy disk technology. Tap tests indicate media wear caused by repeated access at a single location on the most frequently used tracks. In a recent OEM evaluation, the DataTrak consistently passed more than 100,000 taps -- or one year's normal use -- with no measurable degradation of signal amplitude. the company reports.
Low media wear is achieved by electronically and mechanically controlling the head landing and take-off dynamics until the needed combination is attained -- a fast approach and slow, soft landing followed by a slow take-off with rapid acceleration. This more constant pressure on the media, thtougb electronic and mechanical dampening of the solenoid, thus reduces wear and signal deterioration.
Also, the DataTrak 8 drive's peak-topeak signal amplitude tests out at about 40 percent higher than the stated level for typical, dual-sided, double~density drives, says Qume.
The company also notes that a new head design reduces bit shift, which is caused by recording effects, temperature and humidity changes, and other factors. Bit shift can cause a recorded data bit to move out of the timing window in which it is to be read. Customer evaluations have shown DataTrak's bit-shift characteristics to be the best currently available in the industry, according to the company.
All subassemblies, including electromechanical components, can be disassembled and assembled with a screwdriver. All critical components are aligned by mounting on a single- piece, cast baseplate. All critical position-sensitive components, including index sensors, the file protect sensor, and the track 00 sensor, are in fixed locations. The dtive's dual heads are positioned by a stepper motor with a steel band actuator subsystem.
The DataTrak 8 stores 1.6M bytes of unfo...