2. Reboot your computer to DOS.  If you are using Windows 95, simply shutdown and click the choice, "Restart the computer in the MS-DOS mode."

3. Y2000.ZIP is a zip file that produces two files: 2000.EXE and README. TXT. Execute the file 2000.EXE by typing the path to the file followed by the file name. For example, if you stored 2000.EXE in c:\temp you would execute the file by typing at the C prompt: c:\temp\2000.exe.

4. Execute the test program by entering 2000.EXE at the DOS prompt.

5. The test results will be displayed on your monitor.

6. You can also copy YMARK2000 to a floppy diskette and run the tests from a floppy:

a) Boot to DOS.

• Put a blank or unused diskette into drive A.
• From the DOS prompt, type in the command: FORMAT A: /S
• Copy the file 2000.EXE to drive A.
• Leave the diskette in the drive and reboot the system.

b) Execute 2000.EXE

• At the DOS prompt, type in the command: 2000

c) Read the results on your monitor.

• As YMARK2000 executes, watch the test
• A summary of test results is shown at the end of the test

YMARK2000 performs the following tests:

• Verify MC146818 RTC compatibility. This test ensures that the date and time indices are compatible to the MC146818 and the data is in packed BCD format. Some non-DOS based operating systems, like UNIX, do not use the BIOS but use drivers to access the clock directly. This test ensures that the clock is a Motorola MC146818 compatible chip. If the chip is not compatible, then these "other" operating systems or programs that read the clock directly may fail.
• Verify real-time progression from December 31st, 1999 to January 1st, 2000. If real-time support fails, then the ability to set the date manually is checked.
• Verify recognition and support of leap years from 2000 through 2009.

NSTL considered including a power cycle test to confirm the retention of century information. Although conceivable, it is highly unlikely that a BIOS reporting a correct century in real-time will fail after a power cycle. Nonetheless, a reboot test is an important part of the total Year 2000 test process.

YMARK2000 provides batch file support:

An explanation for programmers:

Error levels are indicated by bit fields.  Since multiple errors can be detected, the sum of the error bits are returned.  For example, error level 6 (The Year 2000 is not supported) is a combination of BadProgression and BadManualSet (2+4).

   struct {
     int BadRTC         :1;  // 1, The hardware clock is bad
     int BadProgression :1;  // 2, Progression to 2000 does not occur
     int BadManualSet   :1;  // 4, Cannot manually set 2000
     int BadLeapYear    :1;  // 8, Error in leap year support
     int AwardBIOS      :1;  // 16, An Award BIOS is in use
     };

Definition of YMARK2000 error levels:

Incompatible MC146818: A hardware fix may be required due to an incompatible clock. OR The BIOS is using the clock in an incompatible fashion in which a BIOS upgrade may fix the problem.

Leap year is not supported: A hardware fix may be required due to an incompatible clock.

Progression to Year 2000 not supported: A BIOS upgrade may be required.

The Year 2000 is not supported: A BIOS upgrade may be required.