What PC? 1997 October/WPCOCT97.iso/YEAR2000/YEAR2000.TXT

Text File | 1997-03-16 | 13.6 KB | 327 lines

Year2000.Com v2.16  1997-03-17  (AMIBIOS information)
The executable file name of previous versions was Year2000.Exe.


Tom Becker
The RighTime Company, Miami, USA
Voice: [phone]
Email: [e-mail]
Web:   www.RighTime.com
BBS:   [phone]


Year2000.Com (formerly Year2000.Exe) is a small resident program for
DOS, OS/2 and Windows that fixes the year 1999 to 2000 date change
flaw of the CMOS RTC in AT-class PCs and PS/2s, 286 through Pentium
and its clones.  It works, and it's free for personal, non-business
use (a licensed business version is available; see below).

This program or its documentation can change from time to time.  If
you did not get this from

     www.RighTime.com

it's worth a visit to see if there's been a more recent version made
available.  Our BBS at [phone] is another source.


     Introduction:

A serious problem was designed into the PC in 1984 (and into many
applications since) and remains a problem today: most computer
systems will not gracefully enter the next century, only a few years
away.  The system date will probably be incorrect - without
assistance, anyway - on 2000-01-01 or later because of a hardware
design flaw.  Similarly, many software applications will misbehave
as the year 2000 is approached and passed, too, even if the system
date is correct.

As this is written, machines are being produced that contain a BIOS
that exerts measures intended to cure the CMOS RTC century problem;
it's probably safe to expect that these will become the norm
eventually.  None of these new BIOSs that we've seen solve the
entire problem, however, since they make no attempt to correct the
CMOS RTC century byte in real time, some only correct it at boot,
and some simply misreport the hardware date and make no effort to
correct it at all.

Some BIOSs will supply 2000 to the operating system, even though the
hardware date is really 1900.  Any application that uses the CMOS
RTC date (rather than the operating system date) will still fail at
the moment of the century change, even on machines that sport a
'year 2000 compliant' BIOS.  Many time-and-attendance packages,
machine automation, data acquisition, and instrumentation and
process control applications are susceptible since their developers
long ago learned to distrust the operating system clock/calendar,
opting instead for the relative stability of the hardware clock.

Excepting these recent BIOS-equipped machines, virtually 100% of the
PCs in use today will fail to advance the date to year 2000 under
any circumstance; this program will help those machines that are
still in service then.

We suggest that you install Year2000 now to be certain that your
machine is corrected automatically.


     It's a Hardware Design Problem:

The standard PC computer system maintains two system dates; one is
in the CMOS Real Time Clock chip - a hardware component that is
normally on the machine's motherboard - and one is in the DOS (and
Windows) operating system software.

These two dates are represented differently.  The CMOS RTC date is
kept as century/two-digit-year/month/day and the DOS date is kept as
days-since-1980/01/01 which is converted to
four-digit-year/month/day when any program asks for it.  When DOS
boots, it normally initializes its current date by reading the date
in the CMOS RTC and converting it to days-since-1980/01/01.  DOS
maintains its date as long as the system is running; the CMOS RTC
hardware maintains its date whether the system is running or not,
but it does not maintain the century.  In the CMOS RTC, year 99
overflows to 00 and the century remains unchanged so the effective
year becomes 1900; in DOS, year 1999 overflows to 2000.  So until
the system is rebooted, there will appear to be no problem with the
transition from year 1999 to 2000; but trouble lurks in the CMOS RTC
date, which has become year 1900.

If, when DOS boots, it reads an out-of-range date from the CMOS RTC,
as 1900 is, the date conversion algorithm (to days-since-1980/01/01)
calculates an erroneous 1980-01-04; that's what the DOS date will
become after rebooting the system after the year 2000 transition if
the CMOS RTC exhibits the standard flaw.

A few specific BIOSs cause behavior other than the standard flaw.
Importantly, the Award v4.50 series BIOS might not allow any date
after 1999 and the Award v4.51PG BIOS - currently common among
Pentium- and 486-based machines reports 2096 under some
circumstances.  Some AMI BIOSs will force the CMOS RTC date to
1980-01-01 at boot.  These BIOSs can not be corrected by software;
they must be upgraded.  See references, below.


     A Test:

[The following tests require that you simulate December 31, 1999 and
January 1, 2000 dates in your machine.  Before you change your
system date to the future, consider whether your system software
might automatically do something that you'd rather avoid.  For
example, if you run a scheduler that will automatically delete
events in the past it might discard your appointments for next week
if you set the date beyond next week.  To avoid such effects, either
temporarily disable the susceptible software or temporarily remove
it from the Startup group or folder.  If you run no software that
runs automatically and is triggered by date, you need not take any
special precautions.  Alternatively, you might consider booting from
a bootable diskette to avoid your main applications altogether.]

You can easily determine if your system suffers the year 2000 CMOS
RTC flaw.  From a DOS prompt (ideally with no CONFIG.SYS or
AUTOEXEC.BAT) perform the following steps:

Power off test:
     C:>DATE 12-31-1999
     C:>TIME 23:59
- Power off for more than one minute,
- Power on.  Allow the system to boot.
- Check the DOS date.  It should be 01-01-2000.  If it's not
     (it's usually 01-04-1980), the machine exhibits the
     year 2000 flaw.

Power on test:
     C:>DATE 12-31-1999
     C:>TIME 23:59
- Wait for more than one minute; you can watch an on-screen
     clock if you like (but not the BIOS Setup clock screen).
- Check that the DOS year has changed to 2000.
- Reboot.  The DOS year should still be 2000.

While you're at it, check to see if your year 2000 is a leap
year (see references below):
     C:>DATE 02-29-2000
- If you get an error, the BIOS is incorrect.  Year 2000 will
     be a leap year, so this set should be valid.

Don't try to do these tests from the BIOS Setup screen.  The BIOS
will likely wrap the date from 12-31-1999 to 01-01-1980 (or 1994),
not to the normal 01-01-1900, invalidating the test.

If you try these tests with Year2000.Com installed, you should see
correct results.  [If you do not see correct results, please report
it so we can investigate your machine type.]


     A Solution:

Assuming the user remembers to do so - a critically important detail
- this erroneous DOS date can usually be corrected by simply setting
the date to what it should be; DOS will (via the BIOS) set the CMOS
RTC century correctly so subsequent boots will yield the correct
date.  The date will be incorrect, though, until the correct date is
set (a network login will usually set the date).  Or, if
Year2000.Com is installed, the century correction will happen
automatically.

Year2000.Com applies a simple rule: if the CMOS RTC two-digit year
(in CMOS address 9) is less than 80 the century (in CMOS address
50d, or 55d for PS/2 machines) is assumed to be 20, otherwise the
century is assumed to be 19.  This makes the resulting year range
1980 through 2079 rather than 1980 through 2099, the usually
expressed limits, but in 2079 these machines will be relics at best,
so it's doubtful that this will be a practical detriment.  The
century change rule must be applied at two times: at boot, to cover
the likelihood that the year change has occurred while powered off,
and, when powered on, at each time the CMOS RTC two-digit year
changes (which only occurs once each year at New Year's Eve
midnight). Year2000.Com uses standard periodic interrupts to test
for this occasion. If, when Year2000.Com loads, the year is already
2000 or greater, it will not remain resident since the program then
serves no purpose.  When it is resident, though, it occupies less
than 700 bytes, uses trivial processor time, and should exhibit no
compatibility problems.


     Installation:

For DOS and Windows:
    Simply execute Year2000.Com early in AUTOEXEC.BAT.

    For example, if you choose to put Year2000.Com in a directory
    you've named Y2K on your C: disk drive, you must place this
    statement in your AUTOEXEC.BAT file:
        C:\Y2K\Year2000.Com

    The program will work properly under DOS through Windows
    95.

For OS/2:
    Drop the Year2000.Com program object in the Startup folder.
    You may select Session options to run in a minimized DOS
    window if you wish; no other settings are required.


    Business licensing:

The RighTime Company offers four types of license for business use
of Y2KPCPro, the licensed version of Year2000.Com.  Licensing is
inexpensive.  Please contact us for details.

The RighTime Company
590 Southwest 23 Avenue
Miami, Florida 33135-3123 USA

Email:     [e-mail]
Web page:  www.RighTime.Com

Fax:       [phone] or [phone]
BBS:       [phone] or [phone]
Voice:     [phone] or [phone]


     A Suggestion:

Year2000.Com is an extract of RighTime - the learning high precision
system clock manager.  RighTime solves all of the system clock
problems that are inherent in the AT-class PC and produces a clock
that is reliable, highly accurate and secure.  Reliably correct
system time is important; RighTime should be running on your
machines to be certain that yours is correct.


     Copyright notice:

Y2KPCPro, Year2000.Com, Year2000.Exe and this file (Year2000.Txt)
are Copyright 1995-1997, GTBecker, Miami.  All rights are reserved.

For personal use, permission is granted to freely copy, distribute
and use this program in its complete, unmodified form including this
text file.  In business service, this program may be used only for
evaluation; a low-cost, licensed version of this program (Y2KPCPro)
is available.  Contact us for details.

No warranty of performance or suitability is expressed or implied.
Every effort has been made to make this software program deliver as
this documentation describes, but the correctness for your
application or environment cannot be assured.  The RighTime Company
cannot assume responsibility for the failure of this software
program, nor for any consequence of its use.  You are encouraged to
test the applicability of this program to your requirements.


     References:

Is the year 2000 a leap year?
          "The year 2000 will be a leap year.  Century years
     (like 1900 and 2000) are only considered leap years if
     they are evenly divisible by 400.  Therefore, 1700,
     1800 and 1900 were not leap years, but the year 2000
     will be a leap year."
          "To understand this, you need to know why leap
     years are necessary in the first place.  Leap years are
     necessary because the actual length of a year is [about]
     365.242 days, not 365 days, as commonly stated.
     Therefore, on years that are evenly divisible by four
     (like 1992, for example) an extra day is added to the
     calendar on Feb. 29.  However, since the year is
     slightly less than 365.25 days long, adding an extra
     day every four years results in about three extra days
     being added over a period of 400 years.  For this
     reason, only one out of every four century years is
     considered as a leap year."

     from NIST:
     http://www.bldrdoc.gov/timefreq/faq/faq.htm


AMIBIOS information:

     Some AMI BIOSs will reset the CMOS RTC date to 1980-01-01 at
     boot; these BIOSs must be upgraded.  AMI will support the AMI
     BIOS on AMI motherboards, but AMI will not support AMIBIOS
     problems on non-AMI motherboards; you must contact the OEM or
     motherboard manufacturer.

     According to AMI, "All current versions of AMIBIOS 95, core
     date 7-15-95, and future versions of AMIBIOS are year 2000
     compliant.  All previous OEM versions of AMIBIOS can be changed
     only by the system OEM to support the year 2000 feature.  This
     change can be given directly to the system OEM from American
     Megatrends."

     from AMI:
     http://www.amibios.com/2000.html

          American Megatrends, Inc.
          6146-F Northbelt Parkway
          Norcross, GA 30071-2976 USA
          770-246-8600 (Voice)
          770-246-8645 (AMIBIOS Technical Problems)
          http://www.megatrends.com
          http://www.amibios.com


Award v4.50G and Award v4.51PG BIOS information:

     If you have a machine that uses the Award v4.50 series
     BIOS (most commonly v4.50G), you might find that the
     BIOS (and therefore the CMOS RTC) will not accept any
     dates after 1999 nor prior to 1994.  Also, the Award
     v4.51PG BIOS apparently yields year 2096 under some
     circumstances.  Award tells us that you should be able
     to get a BIOS upgrade from the OEM (the machine or
     motherboard's supplier or manufacturer).  If you are
     unable to determine the OEM or can't contact them, get
     the BIOS part number from the top of the CMOS Setup
     screen and contact Award directly.

          Award Software International Inc.
          777 East Middlefield Road
          Mountain View, CA 94043-4023 USA
          415-968-4433 (Voice)
          415-968-0274 (Fax)
          [e-mail]
          http://www.award.com