Manchester Decoder

Oct 30, 2006 25 Replies

No, there cannot be pathological bit patterns in Manchester encoding. It can handle over 10,000 consecutive bits of consecutive 1's, 0's, alternating, or any other pattern. That is why it was chosen for disk drives over 30 years ago. It got eclipsed by FM. MFM, MMFM, RLL, GZR, and other techniques about 20 years ago that achieved higher bit rates with equal flux change rates (especially for the last three).

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller

Faux ignorance does not really become you.

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller

Disc drives use special sync bytes, this makes Manchester workable. A continuous string of all ones or all zeros still looks identical.

Luhan

That was/is not Manchester, that was/is FM.

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller

Sync bytes and preambles are not unique to Manchester, besides for short transmissions (bit sequences) no sync byte is needed or used for Manchester or FM.

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller

But it only takes a single 1/0 or 0/1 transition to get it unconfused forever after.

John

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