[nukkad] 10 greatest computer bugsof all times

[BRIJESHBK <>]

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Worth readable, if you haven't yet.
 
 
 10. Mariner 1 Venus probe loses its way: 1962
   A probe launched from Cape Canaveral was set to go to Venus.  
After takeoff, the unmanned rocket carrying the probe went off course,  
and  NASA had to blow up the rocket to avoid endangering lives on  
earth. NASA later attributed the error to a faulty line of Fortran code.  
The report stated, "Somehow a hyphen had been dropped from the  
guidance  program loaded aboard the computer, allowing the flawed signals  
to command the rocket to veer left and nose down...Suffice it to  
say, the  first U.S. attempt at interplanetary flight failed for want of a

hyphen." The vehicle cost more than $80 million, prompting Arthur C.
Clarke to refer to the mission as "the most expensive hyphen in  history."

 9. Radiation machine kills four: 1985 to 1987
    Faulty software in a Therac-25 radiation-treatment machine made  
by Atomic Energy of Canada Limited (AECL) resulted in several cancer  
patients receiving lethal overdoses of radiation. Four patients died.
When their families sued, all the cases were settled out of  court. A
 later investigation by independent scientists Nancy Leveson and  
Clark  Turner found that accidents occurred even after AECL thought it  
had  fixed particular bugs. "A lesson to be learned from the Therac-25  
story is that focusing on particular software bugs is not the way  to
make a safe system," they wrote in their report. "The basic  
mistakes here involved poor software-engineering practices and building a  
machine that relies on the software for safe operation."


 8. AT&T long distance service fails: 1990
    Switching errors in AT&T's call-handling computers caused the   
company's long-distance network to go down for nine hours, the  
worst of several telephone outages in the history of the system. The 
 meltdown affected thousands of services and was eventually traced  
to a single faulty line of code.

      7. Patriot missile misses: 1991
      The U.S. Patriot missile's battery successfully headed off many  
Iraqi Scuds during the Gulf War. But the system also failed to track  
several  incoming Scud missiles, including one that killed 28 U.S.  
soldiers in a barracks in Dhahran, Saudi Arabia. The problem stemmed from a

software error that put the tracking system off by 0.34 of a second.
 As Ivars Peterson states in Fatal Defect, the system was  
originally  supposed to be operated for only 14 hours at a time. In the  
Dhahran  attack, the missile battery had been on for 100 hours. This meant  
that the errors in the system's clock accumulated to the point that  
the  tracking system no longer functioned. The military had in fact  
already  found the problem but hadn't sent the fix in time to prevent the  
 barracks explosion.

 6. Pentium chip fails math test: 1994
  The concept of bugs entered the mainstream when Professor Thomas  
Nicely at Lynchburg College in Virginia discovered that the Pentium chip  
gave incorrect answers to certain complex equations. In fact, the bug  
occurred rarely and affected only a tiny percentage of Intel's
customers. The real problem was the nonchalant way Intel reacted.  
"Because we had been marketing the Pentium brand heavily, there
 was a bigger brand awareness," says Richard Dracott, Intel director of  
marketing. "We didn't realize how many people would know about
 it, and some people were outraged when we said it was no big deal." Intel  
eventually offered to replace the affected chips, which Dracott says
cost the company $450 million. To prove that it had learned from  its
 mistake, Intel then started publishing a list of known "errata,"  or
 bugs, for all of its chips.

 5. Intuit's MacInTax leaks financial secrets: 1995
 Intuit's tax software for Windows and Macintosh has suffered a  
series of bugs, including several that prompted the company to pledge to  
pay any resulting penalties and interest. The scariest bug was  
discovered  in March 1995: the code included in a MacInTax debug file
allowed  
Unix  users to log in to Intuit's master computer, where all MacInTax   
returns were stored. From there, the user could modify or delete returns.
 Intuit later ended up winning BugNet's annual bug-fix award
 in 1996 by responding to bugs faster than any other major vendor. 

 4. New Denver airport misses its opening: 1995
 The Denver International Airport was intended to be a  
state-of-the-art airport, with a complex, computerized baggage-handling
system and  
 5,300 miles of fiber-optic cabling. Unfortunately, bugs in the
baggage  system caused suitcases to be chewed up and drove automated  
baggage carts into walls. The airport eventually opened 16 months late,  
$3.2 billion over budget, and with a mainly manual baggage system. 

 3. Java opens security holes; browsers simply crash: 1996 to 1997  
 All right, this is not a single bug but a veritable bug
 collection. We include this entry because the sheer quantity of press
coverage  
about bugs in Sun's Java and the two major browsers has had a profound  
 affect on how the average consumer perceives the Internet. The
conglomeration of headlines probably set back the e-commerce  
industry by five years. Java's problems surfaced in 1996, when research at
the University  
of  Washington and Princeton began to uncover a series of security  
holes  in Java that could, theoretically, allow hackers to download  
personal  information from someone's home PC. To date, no one has reported  
a real case of a hacker exploiting the flaw, but knowing that the  
 possibility existed prompted several companies to instruct
employees  to disable Java in their browsers.
Meanwhile, Netscape and Microsoft began battling in earnest in  
the much-publicized browser wars. That competition inspired both  
companies  to accelerate the schedules for their 4.0 releases, and the  
result has  been a swarm of bugs, ranging from JavaScript flaws in
Netscape's  
Communicator to a reboot bug in Microsoft's Internet Explorer.
 Communicator is now in Version 4.04 for Windows 95 and Windows  
NT, six months after its first release. Internet Explorer 4.01, the first  
of presumably many bug-fix versions, arrived in December, two months  
after the initial release of IE 4.0. 

2. Deregulation of California utilities has to wait: 1998
 Two new electrical power agencies charged with deregulating the   
 California power industry have postponed their plans by at least  
three  months. The delay will let them debug the software that runs the  
new power grid. Consumers and businesses were supposed to be able to  
choose  from some 200 power suppliers as of January 1, 1998, but time ran  
out  for properly testing the communications system that links the two  
new agencies with the power companies. The project was postponed  
after a seven-day simulation of the new system revealed serious problems.  
The  delay may cost as much as $90 million--much of which may  
evetually be footed by ratepayers, and which may cause some of the new power

suppliers to go into debt or out of business before they even
 start.


1. The millennium bug: 2000
     For a long time, programmers have saved memory space by leaving  
only   two numeric fields for the year instead of four: 87 instead of  
1987,   for example. When clocks strike midnight on January 1, 2000, this  
 programming shorthand will make millions of computers worldwide
 think  it's 1900, if their software isn't fixed before then. The  
so-called  year 2000 (Y2K) bug has given birth to a cottage industry of 
 consultants and programming tools dedicated to making sure the  
modern world doesn't come to a screeching halt on the first day of the  
next century. Some say that the bug will cause airplanes to fall from  
the sky, ATMs to shut down, and Social Security checks to bounce. At  
the very least, the bug is a huge and expensive logistical problem,  
although most vital organizations now say they will have fixed  
the critical portions of their systems in time. 


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