Browse Prior Art Database

Intelligence Storage (or Communication) System

IP.com Disclosure Number: IPCOM000092860D
Original Publication Date: 1967-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Padalino, M: AUTHOR

Abstract

This is a method of binary recording for magnetic storage of information.

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Intelligence Storage (or Communication) System

This is a method of binary recording for magnetic storage of information.

The method is predicated on the designation of a different bit cell length for zeros and ones. A first binary value is represented by flux reversal occurring in a given length X of the recording medium. The second binary value is represented by no change of magnetization in a length X, followed by a flux reversal in the subsequent length X, thus occupying a length 2X of the medium. Before a record of information is recorded, the total number of zeros and ones in the record is established. The binary value occurring with the most frequency in that record is assigned to the shorter bit cell length, i. e., X. The other binary value is assigned to the longer bit cell length 2X. A suitable prefix is recorded in the address area of the record and used to control the data separation during readout. The encoding of the prefix must be consistent at all times.

Raw data of waveform A is read from the medium by read-write head 5 and applied to variable frequency oscillator 6 which produces a regularly occurring ramp signal. The raw data is gated through And 7 by the vfo output to produce a separated clock signal of waveform D. Detector block 8 employs the vfo ramp to detect the absence of a flux reversal, waveform B, in the first half of the longer bit cell lengths. Single-shot 9 produces a gating signal as in waveform C. Such signal is provided to And 10...