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Re: PRODOS file date query
Michael J. Mahon wrote:
> bloomer_au wrote:
>> I've got a bunch of program and text files I've been editing daily in
>> Applesoft on an 800kb floppy image in Sweet16.
>>
>> When I catalog the disk in either 40 or 80 columns, nearly everything
>> says 'NO DATE' for both modified and created dates. Yet when I catalog
>> the disk with PROSEL, all the correct 2010 modification dates appear.
>>
>> Anyone know why they don't show up by normal cataloging?
>
> I suspect you have a ProSel modified for Y2K by Glen Bredon.
>
> He chose to extend the year range by extending the "year" field
> in the packed date from 0..99 to 0..128, where 100 = the year 2000.
> It is non-standard for this field to be > 99, so anything but his
> utilities will report it as 'NO DATE'.
>
> The "standard" scheme proposed by Apple was to move the "window"
> from 1900..1999 to 1940..2039, keeping all the "year" fields in
> the 00..99 range.
>
> Since standard tools only report the 2-digit year, that approach
> is backward compatible as long as you don't sort by date.
>
> Beverly Cadieux made patches to ProSel and the ProSel Utilities
> that are consistent with the Apple-recommended approach. You may
> wish to use these versions to restore consistent behavior.
>
> -michael
>
> NadaNet 3.1 for Apple II parallel computing!
> Home page: http://home.comcast.net/~mjmahon/
>
> "The wastebasket is our most important design
> tool--and it's seriously underused."
>
00B3B6 1 C9 64 @3: cmp #100 ; >99?
00B3B8 1 90 06 bcc @4 ; no, skip
00B3BA 1 D8 cld ; binary
math
00B3BB 1 E9 64 sbc #100 ; take off
the 100
00B3BD 1 4C B6 B3 jmp @3 ; in case
some doof put >200
My port of EHBASIC does this in CAT... a modulo 100 on the year. "<NO
DATE>" happens only when the whole date is 0 (and undefined behavior if the
month is >12).
-uso.