04488142 is referenced by 48 patents and cites 3 patents.

An algorithm and the hardware embodiment for producing a run length limited code useful in magnetic recording channels are described. The system described produces sequences which have a minimum of 1 zero and a maximum of 7 zeros between adjacent 1's. The code is generated by a sequential scheme that maps 2 bits of unconstrained into 3 bits of constrained data. The encoder is a finite state machine whose internal state description requires 3 bits. The encoder requires a lookahead of one future input vector (2 bits) and a look back at the last channel bit generated during the immediately preceding encoding operation. The error propagation due to a random error is, at most, 4 bits in bursts of 5. The hardware implementation is extremely simple and can operate at very high data speeds.

Title
Apparatus for encoding unconstrained data onto a (1,7) format with rate 2/3
Application Number
6/336488
Publication Number
4488142
Application Date
December 31, 1981
Publication Date
December 11, 1984
Inventor
Peter A Franaszek
Katonah
NY, US
Agent
Roy R Schlemmer
Assignee
International Business Machines Corporation
NY, US
IPC
H03K 13/24
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