Re: AppleWorks limits

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

<Jim.Low@logicbbs.org> wrote:

> Okay, I've been told there is no way to patch AppleWorks 4.x, 5.x to allow
> more than the 16,249 lines or records in WP and DB.  Not without a total
> re-write of the program.
>  
> I wonder if there isn't some way to break that limit -- it's a serious limit
> for me.  I know AppleWorks 2 had a patch written for it that allowed a
> 22,000 line limit -- by disabling the format capability.

Some theorising here:

The limit of 16,249 lines/records is probably a representation limit.
The number is suspiciously close to 16384 (2^14), so my guess is that
the internal representation only has 14 bits to hold the line number,
using the last two bits for something special.

This sort of limitation is impossible to work around, without patching
large parts of an application - assumptions about the line/record format
will be built into most of the code.

I can't think of any specific reason why the limit is not 16383 or
16384, except that several line or record numbers may be reserved for
special flags.

As to the higher AppleWorks 2 limit: there were some major changes in
AppleWorks 3.0, and I expect this included changes to the internal data
structures; this change resulted in the absolute limit of about 16384
lines.

The 22K limit in AppleWorks 2 is likely to be due to the largest
representable file, or data structures for keeping track of the lines.
Disabling features would have been necessary to allocate more memory for
keeping track of the extra data (removing more features might have
allowed for a still higher limit).

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