Talk:Modified Frequency Modulation

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This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.

The article says "MFM allows more than one symbol per flux transition — up to three — giving greater density of data than FM." I think this is nonsense. FM encodes a one as a 11 and a zero as 10. MFM encoding is as shown. They have the same density, given the same clocking; each takes two "possible transition" periods to encode a bit. The reason MFM achieves greater data density is it can be clocked at twice the rate (because there are never two transitions in a row). Or am I totally off-base here? See http://www.storagereview.com/guide2000/ref/hdd/geom/dataMFM.html

Nybbler 23:29, 5 March 2006 (UTC)

It may be confusing, but I think the statement is correct. Your statement is also correct. Mirror Vax 00:34, 6 March 2006 (UTC)

I'm still not seeing it. A one followed by a zero is 0100, two bits with one flux transition. A zero followed by a zero is 1010 or 0010 two bits and one or two transitions. A one followed by a one is 0101, two bits and two flux transitions. A zero followed by a one is 0001 or 1001, again two bits and one or two flux transitions. There's never three symbols with one flux transition.

Nybbler 15:28, 6 March 2006 (UTC)

[edit] Questionable question marks in the examples

It would be nice if the question marks in the examples would be explained somewhere. --89.49.249.90 22:13, 17 August 2007 (UTC)