r WorkgroupsDells Implemented SolutionsTo avoid the need for manual intervention by Dell customers, Dell has modified the BIOS code on Dell systems so that the RTC will automatically update correctly at the century rollover. The Dell modifications consist of corrections to two BIOS functions, once when asked for the date (Read RTC Date function) and once when told to set the date (Set RTC Date function). When either of the modified BIOS set or read functions are performed after December 31, 1999, the century byte will be updated and stored permanently in the nonvolatile portions of the RTC, correct for another 100 years. Both BIOS modifications ensure that the system date will be correct after the century rollover. These BIOS modifications will also correct another error than can occur at the century rollover. On some systems, if the user runs the System Setup program before the OS boots for the first time after January 1, 2000, the ROM setup program embedded in the system, using BIOS calls, will detect the invalid RTC date, 1-1-1900. There are a few different tests that can be done, but all of them have a specific scenario. The first one is the Power-on self test (POST), which is implemented in the BIOS, are designed to assure that the correct date is passed to operating systems that retrieve the date at boot time and maintain it internally after that. The second test is the modifications to the BIOS address those application programs that bypass the operating system to retrieve date information from the BIOS. Another one is an MS-DOS patch program, run each time the system is booted, addresses older systems equipped with a non-flash BIOS that cannot be upgraded economicallyprimarily systems based on intel486 and earlier microprocessors. The MS-DOS patch program corrects the RTC date through BIOS calls. Because it runs at boot-time, the system must be rebooted after the century rollover for the correct date to be implement...
