The Old New Thing

How did the invalid floating point operand exception get raised when I disabled it?

July 3, 2008 Jul 3, 2008 07/3/08

Raymond Chen

Last time, we learned about the dangers of uninitialized floating point variables but left with a puzzle: Why wasn't this caught during internal testing? I dropped a hint when I described how s work: You have to ask the processor to raise an exception when it encounters a signaling NaN, and the program disabled that exception. Why was an ...

Raymond misreads newspaper head… no wait, I didn’t!

July 2, 2008 Jul 2, 2008 07/2/08

Raymond Chen

I have a habit of misreading newspaper headlines, so I simply assumed that this was just another one: Phelps sets word record in 400 IM. (And no, I don't normally read the Rocky Mountain News. The actual headline was printed across the top of the June 30 Seattle Times Sports section, but I couldn't find the headline in the online archives, ...

Uninitialized floating point variables can be deadly

July 2, 2008 Jul 2, 2008 07/2/08

Raymond Chen

A colleague of mine related to me this story about uninitialized floating point variables. He had a function that went something like this, simplified for expository purposes. The infoType parameter specified which piece of information you're requesting, and depending on what you're asking for, one or the other of the output parameters may ...

András Schiff 2006 lectures on the Beethoven piano sonatas

July 1, 2008 Jul 1, 2008 07/1/08

Raymond Chen

In 2006, pianist András Schiff gave a series of eight lecture-recitals covering the complete cycle of Beethoven piano sonatas. Here are all the lectures on one page. (Beware: The metadata on these mp3 files is all over the map.) As an incompetent student of the Beethoven sonatas, I find these lectures absolutely riveting. Note: ...

Windows Vista changed the Alt+Tab order slightly

July 1, 2008 Jul 1, 2008 07/1/08

Raymond Chen

For decades, the Alt+Tab order was the same as the Z-order, but that changes in Windows Vista if you use the enhanced Alt+Tab feature known as Flip, which is on by default on most systems. There are three types of interactive task switching in Windows Vista: Classic Alt+Tab continues to show the icons in Z-order order, but the developer ...

2008 mid-year link clearance

June 30, 2008 Jun 30, 2008 06/30/08

Raymond Chen

Time for the semi-annual link clearance. And, as always, the obligatory plug for my column in TechNet Magazine: Footnotes ¹Yes, it isn't literally powered by RFID. I was spoofing marketing-speak. I apologize to those for whom this did not require explaining...

You don't need that 90 byte whereis program any more

June 30, 2008 Jun 30, 2008 06/30/08

Raymond Chen

Yes, you can write a whereis program in 90 bytes but Windows Server 2003 and Windows Vista both come with a version of , so you don't even need the batch file any more...

GUIDs are globally unique, but substrings of GUIDs aren’t

June 27, 2008 Jun 27, 2008 06/27/08

Raymond Chen

Half of a GUID is worse than none.

The mystery of the garbage lady

June 26, 2008 Jun 26, 2008 06/26/08

Raymond Chen

Last year, my good friend and colleague Sarah transfered from the Redmond offices to Microsoft UK in Reading. One of her most popular lunchtime stories is the mystery of the garbage lady, which she finally got around to posting on her blog. Some of my other favorite stories from her blog: A colleague of mine experienced the ...

The disappointment of people who need to have their hand held from beginning to end

June 26, 2008 Jun 26, 2008 06/26/08

Raymond Chen

Some customers already have the answer but need to have their hand held. My customer wants to enforce a company-wide policy of disabling the "Keep the taskbar on top of other windows" feature. We have confirmed that there is no group policy setting for controlling this setting. Further research reveals the function. The customer wants to ...