Talk:Most significant bit

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The picture in this page is useless without specifying the "weight" of each bit!

exactly. is the example big endian or little endian? i don't understand which is which. - Omegatron 18:40, Jun 8, 2005 (UTC)
The terms big endian and little endian have no meaning within a single byte with the exception that most big endian devices (such as Motorola) number the MSB bit 0 and the LSB bit 7, which most little endian devices (such as Intel) number the MSB bit 7 and the LSB bit 0. In either case, the MSB is the left-most bit while the LSB is the right-most bit. Endianness becomes an issue when you are dealing with multiple bytes. Endianness it a very simple concept, but for someone who doesn't deal with it regularly, it can be quite difficult to grasp. The endianness article should explain it fully, although I haven't read it lately and am not certain whether it provides a sufficient explanation. Jimwilliams57 02:30, Jun 9, 2005 (UTC)
Oh, ok. Well, shouldn't the image indicate that the bit on the right represents the "1's place" and the bit on the left represents 128? - Omegatron 15:09, Jun 9, 2005 (UTC)
Good point. I'll take care of it. Jimwilliams57 02:19, Jun 11, 2005 (UTC)

Alternate meaning of MSB[edit]

Lately I've started seeing another usage of MSB == "Main Stream Blogosphere".

See for instance

http://outsidethewhale.blogspot.com/2005/04/drudges-lament-dispatches-from-msb.html http://www.tnr.com/blog/theplank?pid=4284 — Preceding unsigned comment added by Infrogmation (talkcontribs) 9:32, 10 June 2005‎

That would belong on the MSB disambiguation page, not here, as it's not relevant to significant bits or bytes. Guy Harris (talk) 01:35, 17 January 2016 (UTC)

Furthermore[edit]

It's possible to mathematically calculate the greater of two numbers using the MSB without having to use code branching:

If Y is greater than X then Y-X will have an MSB of 0 If X is greater than Y then Y-X will have an MSB of 1

Therefore (Y x NOT(MSB(Y-X)))+ (X x MSB(Y-X)) will return the larger number.

Proof: 3 - 2 = 1, MSB(3-2) = 0, NOT(MSB(3-2)) = 1, therefore (3 x NOT(MSB(3-2))) + (2 x MSB(3-2)) = 3 x 1 + 2 x 0 = 3

Have fun with that!! —Preceding unsigned comment added by 213.120.253.12 (talk) 16:12, 5 August 2009 (UTC)

Unsigned?[edit]

The binary example image at the right states: "The msb in an 8-bit binary number represents a value of 128 decimal." Should this read "The msb in an 8-bit unsigned binary number..."? I know the word unsigned is mentioned earlier, but it would make sense to use it here as well (to me). --Iaindb (talk) 05:49, 12 August 2009 (UTC)

Use of MSB in negative calculations[edit]

Might be worthwhile noting the historic use of MSB in storing negative numers digitally, now replaced by Two's Complement. Another bit would be added to a number (on the left, effectively a new MSB) and would be used to indicate polarity; 0 for positive, 1 for negative. — Preceding unsigned comment added by A - J - Hadley (talkcontribs) 23:01, 12 September 2012 (UTC)

That's signed magnitude notation; in two's complement, and ones complement, notation, the MSB acts as a sign bit as well. Guy Harris (talk) 01:40, 17 January 2016 (UTC)