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From: marwk@levels.sait.edu.au
Newsgroups: comp.arch
Subject: Hamming code (or other) for 4-bit correction?
Message-ID: <16045.27ed2f20@levels.sait.edu.au>
Date: 24 Mar 91 13:28:40 GMT
Organization: University of South Australia
Lines: 24

Suppose one has 32-bit words and 8 more bits/word for error detection and
correction.

(1) Can the hamming code for 32-bits (requiring 6 bits) be modified
    to detect 2-bit errors (as well as correct 1-bit errors)?

(2) How about correcting 4-bit errors?

It is ok to put 2 or more words together and correct on the lot (eg 512 bytes).
In fact this would be necessary as 2 bits more is not enough for (2), but of
course only 1 more hamming bit is required for every extra power of 2 in the
number of bits the code is produced for.

If the Hamming code cannot be modified then what is another code for this.
I cannot find anything in the literature and I cannot work it out with
a pencil.  Maybe I am looking in the wrong place?

Thank you.
Ray
--
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