Epic Computer Bugs

In the year 1945, a club called “Buggy Computers” was born when a moth got trapped between the adders and multipliers in Panel F, Relay #70 of the Harvard Mark II system. The moth made itself a permanent place in history, it was trapped and taped into the computer’s logbook with the statement: “first actual case of a bug being found.”
Sixty years have passes and computer bugs still exist. Bugs don’t just exist in computational systems, they may also be present in cars, music systems, and pacemakers.

Here is the list of some of the most embarrassing bugs in the history of computer:

July 28, 1962 – Mariner I space probe

A bug was present in the space craft’s trajectory routing system, which caused the space craft to divert from its original trajectory and run astray. The engineers had no option but to self-destruct the rocket over the Atlantic Ocean. On investigating the problem, it was found that there was a misinterpretation of the theoretical formula written and the one updated in the software.

1982 – Soviet gas pipeline

CIA had always made their position clear. They had once planted a bug in the operating software of the trans-Siberian gas lines, the codes of which Soviet had obtained by helping in the covert leakage of CIA classified files. The bug back-fired and misdirected abundance of explosive gas into the gas lines resulting in the largest non-nuclear explosion in History.

1985-1987 – Therac-25 Medical Accelerator


Therac-25 was a radiation therapy device that delivers powerful radiations. However, Therac-25 is based on an operating system that had been developed by a programmer with no formal training. This resulted in a bug called the Race condition. Even though a therapist can configure the machine to emit high power rays, it sometimes happened that the rays emitted were away from target metal. This resulted in five deaths and many injured.

1988 – Buffer Overflow in Berkeley Unix Finger Daemon

Also called the Morris worm. This was the first internet worm to come into existence. Using the buffer overflow, this worm could infect 4,000 to 8,000 computers per day. The specific code is a function in the standard I/O library routine called gets () used to text line over the network. Gets () does not limit its input. As a result a large input can help the worm take over the computer.

1988-1996 – Kerberos Random Number Generator

As a result of the utter negligence of the developers of the Kerberos Random Number Generator, a bug always existed in the system. The generator was never actually seeded with a proper random number seed. Thus, for eight years it was absolutely possible to break onto any computer system that relied on Kerberos for authentication. It is unknown if this bug was ever actually exploited.

January 15, 1990 – AT&T Network Outage

A bug in the new release of the software that controls AT&T’s #4ESS long distance switches causes the huge computers to crash whenever they receive a “recovery from crash” message from its neighboring computers.
Solution to the problem? Engineers installed the older version once again.

1993 – Intel Pentium Floating Point Divide

A chip bug in the highly promoted INTEL silicon caused an error that resulted in the loss of accuracy when floating point numbers were divided. The company initially agreed to change the chip only when users could prove that they required very high level of accuracy, however, later the company agreed to change the chip for every complaint. This made the company inherit a loss of $475 million.

The Mars Climate Orbiter doesn’t orbit: A havoc was caused at different levels of the program. There was uneven payload, resulting in a torque of the space probe. The project managers failed to pay attention to the various departments working with various parts of the space-shuttle. This resulted in wide spread miscalculations as different departments used different units of measurement. The result: The thrusters were 4.45 times more powerful than they should have been.

Excel 2007

Calculators can correctly multiply 850 x 77.1, and the answer is 65,535. But in September 2007, it was discovered that Excel 2007 answered 100,000.
According to Microsoft, this error in calculation occurred in 65,535 or 65,536. They also added that Excel calculated the answer correctly but due to a bug, it could not display it correctly.

Also Read: Why “C” is the default Hard Drive In computer?

Patriot missile mistiming

During the first Persian Gulf War, Iraqi-fired Scud missiles were the most threatening airborne enemies to U.S. troops. Once one of these speeding death rockets launched, the U.S.’s best defense was to intercept it with an anti-ballistic Patriot missile. The Patriot worked a bit like a shotgun, getting within range of an oncoming missile before blasting out a cloud of 1,000 pellets to detonate its warhead. However, one scud missile did hit the troops and killed 28 of them. The cause was directed at a software glitch that could not estimate the approach time properly.