After a fortnight of extraordinary type, the much-feared computer virus that was supposed to strike the globe's hard drives last Friday simply fizzled. So many warnings were sounded that most computer owners either fed anti-virus programs into their systems or refused to turn the power on during the dreaded M-day. They dodged one disease, but more strains are on the way. The eponymous Friday-the-13th virus is due to strike this week, and the Maltese Amoeba may detonate on March 15. Who creates these things? A disproportionate number seems to originate in Bulgaria or Russia, where writing the smallest, most elegant virus programs has become a matter of quirky pride. Viruses are transmitted either by shared disks (as was Michelangelo) or over telephone lines. The virus program hides in a computer until, activated by a date, time, or some other trigger, it springs to life. The most common virus, Stoned, makes your screen announce: "Your computer is now stoned. Legalize marijuana. " (Regardless of your politics, you don't want this one around; it can damage your files inadvertently.) Solution: either keep your computer isolated--no trading disks, no on-line communication--or else install one of a dozen or so commercially available anti-virus programs that detect and delete the little time bombs. If they can come up with a virus that is hidden, will they next try to extort a business?--as in, pay me $1 million or my virus will destroy your system. In the meantime, money is being made by firms selling anti-virus programs. Egghead software stores logged a 3,000 percent jump in anti-virus sales. Was the threat overblown by the companies that make millions selling anti-virus software? Thanks to the media blitz, no one will ever know what might have happened--an unallied number of computer owners discovered and deleted Michelangelo before it was supposed to strike--on the artist's birthday. The much-feared M-day was   _  .
Friday-the-13th when the eponymous virus was due to strike Friday-the-15th when the Maltese Amoeba would be activated the previous Friday when Michelangelo virus was due to strike the previous Friday which coincided with the artist's birthday