The failure of a personal computer system to correctly deal with dates to rollover from 31-12-1999 to 01-01-2000 is the result of an apropriate interaction between the RTC, the BIOS, the system clock or the operating system.Technically speaking, there are three different clocks co-exist in a PC system, namely :
                                                RTC clock
                                                BIOS clock
                                                OS clock or system clock

      A PC uses a "Real Time Clock" (RTC) to maintain the time/date function at all  time whether it is on or off. When a PC is switched on, the motherboard BIOS  (Basic Input/Output System) will be activated during boot up process. One of   the very first tasks the BIOS does is to get the initial time/date from th RTC  clock. The BIOS will then pass on the Time/Date to the Operating System  when requested by the OS during OS bootstrap.   From then on, the OS will  maintain the OS clock with its internal timing routines.   As a result, the OS and  RTC/BIOS clock operate independently. For 486 PCs and some classic Pentium machines built before 1997, its BIOS  will probably have troubles to intepret the year 2000 properly. This is because  these old BIOSes are not capable of resetting the century value to 20 during  the century change. Therefore, it will generally return to 1980 or 1984 under  OS environment and 1900, 1994 or others in RTC/BIOS clocks readings.  There are many free Y2K test programs such as NSTL's Ymark2000,
Test2000, AMI2000, Millennium Bug Toolkits, etc available in the market for  users to find out if their PC's BIOS is y2K compliant.  Test your PC before the  BUG strike you!  OS clock is generated by PC's operating system such as Microsoft's MS-DOS,  Win3.1x, Win95 and Win98 which are year 2000 ready. It is possible to find  out if the PC can rollover the century correctly at OS-level by manually setting
the system date.
    It is commonly assumed that newer PC (manufactured after 1997) do not  have Y2K hardware problems. In many cases, this assumptions is not always  true. All PCs should be tested including those just acquired.
According to a PC industry's report, more than 90% of the PCs in the world  faill the Real Time Clock (RTC) rollover test, this is due to the BIOS flaw in  most PC motherboards.

[Home] [Profile]  [Product] [Service] [Y2K Info]