NDLI: A new look-ahead code for increased data density

Content Provider	IEEE Xplore Digital Library
Author	Jacoby, G.
Copyright Year	1965
Abstract	This paper describes a novel run-length limited code, termed 3PM. A group of three data bits is converted into six code bits which are represented by the presence or absence of signal transitions. At least two zeros are maintained between two consecutive ones, that is a minimum distance of three positions between transitions, resulting in great reduction of pulse crowding. The minimum distance is assured by a unique merging rule at the boundary of adjacent code words. This rule distinguishes the code from both fixed and variable length codes and results in very simple encoding and decoding algorithms. An actual 50% density increase has been accomplished in saturation recording by using the 3PM code in combination with other electronic techniques. The new code is used in a current ISS/Univac high density disk storage system, featuring 2500 bits/cm (6300 BPI) linear density, 10 Mbits/sec data rate, 338 MByte capacity and one bit in 10 billion raw error rate on conventional Mod-11 head/disk interface.
Sponsorship	IEEE Magnetics Society
Starting Page	1202
Ending Page	1204
Page Count	3
File Size	406556
File Format	PDF
ISSN	00189464
Volume Number	13
Issue Number	5
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	1977-09-01
Publisher Place	U.S.A.
Access Restriction	One Nation One Subscription (ONOS)
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Magnetic heads Magnetic properties Inductance Jacobian matrices Merging Encoding Decoding Disk recording Error analysis Digital magnetic recording
Content Type	Text
Resource Type	Article
Subject	Electronic, Optical and Magnetic Materials Electrical and Electronic Engineering

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