International Business Machines Corporation

Leslie R Zelenka

Nelson K Arter

Arthur B Wills

Ernest William Devore

A forward/backward compatible apparatus and record member achieves multiple density by multiple track widths as well as multiple lineal densities. In a rotating head recorder a single head has a wide write gap followed by a plurality of narrow read gaps. In recording, narrower tracks--i.e., higher densities, the record medium is moved less than the width of the write gap for recording narrower tracks. The narrower tracks have the same width as the trailing read gaps. During readback, all read gaps are simultaneously operative. Signals from one of the read gaps are processed immediately, while signals from the remaining read gaps are buffered until a dead time occurs, such signals are then processed. The same principles are applicable to magnetic card and magnetic disk recorders. A record member of the disclosure employs a table of contents area always recorded at the lower density--i.e., widest track. The table of contents contains indicia indicating the track density as well as the lineal density of the other recording areas. The buffering also is employed to overlap seeks in a disk file for greater data accessibility.

Growing community of inventors

Tucson, AZ, United States of America

Leslie R Zelenka