Spread spectrum – Wikipedia, the free encyclopedia

I have often wondered why there is a BIOS option on modern motherboards for “spread spectrum.” For a server, you probably won’t need this option unless you have EMI regulations to be concerned with.

this method does not reduce total radiated energy, and therefore systems are not necessarily less likely to cause interference. Spreading energy over a larger bandwidth effectively reduces electrical and magnetic readings within narrow bandwidths. Typical measuring receivers used by EMC testing laboratories divide the electromagnetic spectrum into frequency bands approximately 120 kHz wide.[2] If the system under test were to radiate all its energy in a narrow bandwidth, it would register a large peak. Distributing this same energy into a larger bandwidth prevents systems from putting enough energy into any one narrowband to exceed the statutory limits.

Basically, if you have radio signals or display signals that are operating near your CPU frequency, you would be interested in using this to avoid peak interference and specific frequencies.

Spread spectrum – Wikipedia, the free encyclopedia.

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Why Seattle Is Not Like Silicon Valley

Originally posted on TechCrunch:

Editor’s note: Anne Seckinger is a writer interested in the intersection of technology and business.

The stories of Silicon Valley millennials competing, succeeding and failing spill out of the region faster than most journalists can type. The region excels in churning out startups, thanks to the abundance of venture capitalists, the plethora of reporters and the proximity of like-minded techies.

The term “Silicon Valley” is practically synonymous with “tech startup” because startups are the business of Silicon Valley, and entrepreneurs are the output. However, companies that make the greatest impact disrupt present-day societal expectations and norms; the allure of startups is that they dare to surprise and challenge consumers. Thus, how disruptive in the market is it to launch a startup in Silicon Valley when the environment is designed to produce entrepreneurs?

Many technology professionals from across the world relocate to Seattle because of the city’s potential to reward daring…

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CSS pulldown menus, the trick

The real trick to css pulldown menus is the :hover pseudo selector. You knew that. However, the insight comes in learning that the :hover pseudo can be used anywhere in the middle of your CSS selector. This allows you to build up the a selector representing a mouse action that selects a child element of what the mouse it on.

Here is some html:

(span id="menu")
(h3)a category(/h3)
(ul)
  (li)item 1(/li)
(/ul)
(/span)

Now here is how you hover over the over H3 to get the sub menu to raise:

#menu {
   width: 2in;
   height: 2em;
   position: relative;
}
#menu ul {
   display: none;
   position: absolute;
}
#menu h3:hover ul {
   display: block;
}
#menu ul:hover {
   display: block;
}

That h3:hover ul trick is gold!