Bug, computer

This would affect every business that was linked to a computer juid the commotion and hysteria tliat surrounded the Y2K bug were due to the present age s dependence on computers. For c.xamplc, it was feared that the go eminent s computer system would print social security checks with amounts seen in the year 1900 and that banks would calculate dividends based on interest rates from the year 1900. The problems could have been catastrophic. Fortunately, tlie response to the "potential Y2K disaster was effective in that most corrections or patches were made before the year 2000. However, these corrections were costly and required large amounts of money to be spent." ... 

Although computer equipment is used differently to other field equipment, raw data are being generated consequently, maintenance records are required. All maintenance and repairs to the computer system need to be recorded. For example, software and hardware maintenance records would include system/program updates, disk scans, and defragmentation (e.g., preventative maintenance). Repair records might include communication with the software developer about problems/bugs and steps taken to fix any software or hardware problems. Documentation must include whether the... 

For programs that are to be purchased, the user should determine whether the supplier will assist him in training people to use the program and in initially getting any bugs out of it that may appear when it runs on the user s computer. This can save a lot of time and money because the supplier has men familiar with the program, and the user does not. 

We close this section with one more note on careful nomenclature. A code renders a model into a set of instructions that can be understood by a digital computer. Thus, if one applies a particular model, let us say the molecular mechanics model called MM3 (which will be described in the next chapter) to a particular problem, say the energy of chair cyclohexane, the results should be completely independent of which code one employs to carry out the calculation. If two pieces of software (let s call them MyProg and YourProg) differ by more than the numerical noise that can arise because of different round-off conventions with different computer chips (or having set different tolerances for what constitutes a converged calculation) then one (or both ) of those pieces of software is incorrect. In colloquial tenns, there is a bug in the incorrect code(s). 

Can rigorously computed long-range forces be significant How big can a bug be and still hold onto a ceiling by van der Waals forces ... 

In the approach to Year 2000, regulatory authorities tended to survey and monitor the preparations being made by pharmaceutical and healthcare companies to cope with the feared millennium bug rather than conduct detailed computer validation inspections. This factor seems to have delayed comprehensive inspections of computer vahdation. A few sporadic citations for the noncomphance of isolated computer systems arose in 1999, but there were no prominent censures in this area. 

Some program bugs are easy to recognize The program crashes and you are told what kind of error you made. Or worse, the computer locks up. These are the deadly, or fatal, bugs. 

A bug happens when the programmer says one thing and the computer either doesn t know how to do it or does something very different. 

It s almost as if the computer broke the program in two and pasted the line in its proper place. But this cut-and-paste feature, usually quite handy, can become a curse which results in two kinds of program bugs. 

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