Claris CAD: Not Zooming to 3200%

Why can't I zoom to 3200 all the time?

This information was provided by Claris Corporation on 16 March 1998, and incorporated into Apple Computer's Tech Info Library.
The zooming capacity of Claris CAD is based on the size of the document. A one page document can be zoomed up to 3200%, at the largest size 100 X 100 inches, the user can only zoom to 400%. This is due to a limitation within the QuickDraw coordinate system.

Here are the highest zoom levels allowed for the following page sizes:
A ....... 3200
B ....... 1600
C ....... 1600
D ....... 800
E ....... 800
Published Date: Feb 20, 2012