Understanding Bugs and Patches

By Sandy Berger

The current glossary of computer terminology includes two important words: bug and patch. In an ideal computer world, the average computer user would never have to learn about computer bugs and would have no need of dealing with software patches. Unfortunately, we don't live in the ideal computer world, and bugs and patches are a part of our everyday computing. So if you don't yet know about these high-tech aggravations, read on. This information is critical to today's computer user.

A computer bug is an error or defect in computer hardware or software that causes the computer or the computer program to malfunction. The first computer bug is said to have been a moth that was found squashed between the points of an electromechanical relay in the Mark II computer in 1945. This moth caused the entire computer to shut down. When the moth was removed, it was affixed to the computer's log with a scribbled note that read, "First actual case of bug being found." When the computer operators removed the moth, they claimed to have "debugged" the computer, thus introducing the term "debugging a computer program." By the way, this first bug is now housed in the National Museum of American History at the Smithsonian, and yes, someone who answered correctly that the first bug was a moth won a million dollars on the "Who Wants to be a Millionaire" television game show.

Just for the sake of accuracy, I must tell you that Edison used the word "bug" in the 1800s, and some say the word goes all the way back to Shakespeare. But whatever the origin, the word "bug" is now universally accepted as a problem with a computer. And do we have bugs!! Hardware bugs are not terribly prevalent, but today's software seems to be riddled with bugs that were not found before the software was released. This brings us to our next concept: patch.

A patch is an actual piece of computer code (instructions that tell the computer what to do) that is inserted (or patched) into the executable program. Normally a computer program is written in a programming language like C++, Visual Basic, or Cobol. This is called source code. The source code is run through a compiler, which translates that language into a set of instructions called object code. Then the object code is passed through a link editor, which transforms it into machine code. (Don't worry; there won't be a quiz on this! But you never know, some of these facts might supply the answer to another "Millionaire" question.) A patch is called a patch because it is really not integrated with the machine code. Instead, it is a piece of object code that has been written to correct a problem. It is like a band-aid that is applied to a cut or scrape, so patch is really an accurate term.

When a computer manufacturer finds a bug in their program after the program has been released to the public, they issue a patch that corrects the problem. This is usually posted on the manufacturer's Web site along with instructions on how to download and install the patch. If you know how to download a program, the process will be very similar and relatively easy.

Patches are issued not only for software bugs, but also for other problems found in the software. Patches correct flaws, holes, and vulnerabilities that allow a hacker or a virus writer to use the software to gain unauthorized access to the computer running the program. When a manufacturer posts a patch to their software, it may correct a bug that made the software perform poorly, or it may plug a hole that viruses and hackers use. (Sometimes, although more rarely, manufacturers also use patches to add features to the software.)

Bugs and patches are aggravating because they are so abundant in today's computer world. The computer user must pay attention and download these patches to ensure smooth computer operations, security, and virus protection. It is especially important to download and apply patches related to the operating system and Internet browser. Microsoft sometimes calls these "updates" to avoid the negative connotation of the word "patch."

If you are lucky enough to be using Windows XP, the operating system itself will notify you when a critical patch or update for the software is available. If you are using Windows 98 or Me, click on Start, choose Windows Update, and follow the directions. Better yet, use the Windows Task Scheduler to make this an automated activity. Click on Start - Programs - Accessories - System Tools - Scheduled Tasks - Windows Update. Internet Explorer users will find updates for this program are included with the Windows updates. Netscape users will find that Netscape often releases a new version when an accumulation of patches is available. AOL users will find that the AOL software updates itself automatically, but patches for Windows and Internet Explorer will still be necessary.