Hi, I think Margo stated the reason why you would want to use the Casio
AC Adapter- the others simply don't put out the right juice.
If you check thru the archives for this list, going back perhaps as far
as May 95, you'll find posts from people who've used both generic, and
the adapter that Tandy lists for the zoomer, with the result being
that their batteries ran down. If the zoomer doesn't detect the right
current coming in from the AC Adapter, it will continue to draw from
the batteries.
Hope this helps
Blaine
Quality Assurance
Sikorsky Aircraft
bboxwell@sikorsky.com