Re: Y2K and P8 TN #28 (Re: No-Slot Clock)

[dempson@actrix.gen.nz (David Empson)]

TEXAS II - AppleWorks <a2mg@aol.comNoMail> wrote:

> Glen's solution of years 100 and up allow the directory to sort by date
> with years 00 (actually 100) AFTER 99. Even older versions of AppleWorks
> _data bases_ sort with 00 dates being newer than 99. This is something we
> couldn't do in the 00 to 99 world, when 00 dates are relegated to the
> oldest part of the list.

The only reason that this would not work is if the application doing the
directory sort regards the date as a plain 16-bit number (or date/time
as a 32-bit combined value) and does a standard sort on it.

This is not correct behaviour for Y2K-compliant ProDOS dates.  The
correct behaviour is to split off the year, modify the value so that it
can sorted easily (e.g. add 88 then mask with 127), and sort the result.
An alternative is to prepend the appropriate century, which has the same
effect, but requires sorting data larger than 32 bits.

In other words, applications which support sorting by date need to be
modified to support the documented date format.

> Glen's solution also fixes day of the week and problems with functions like
> @Today.

Presumably in pre-compliant versions of AppleWorks.

It is unfortunate that AppleWorks 4.0 and later have such excessive
machine requirements.  It would have been very useful if Claris could
have released a "3.0.1" which had Y2K fixes without the newer features
in the later versions.  This would allow 128K machines to use a
correctly implemented AppleWorks.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand