Apple ][+ Z-Card

[steve.townsend@rook.wa.com (Steve Townsend)]

Apple ][+ users
    
Z-80 Card
    
    Yesterday I was helping a new user configure his
machine and find some software that he could use.  As I am
not very familiar with the ][+, it was mostly a trial and
error process.  
    
    When attempting to boot some programs, we got a
message saying that this program could not be run without a
Z-80 Card installed.  As luck would have it, I had one laying
around from a parts deal I made a year ago, so we put it into
slot 3.  It worked.  Now he can run some programs that he
could not run previously.
    
    What did we do?  What IS a Z-Card?  Why is it
necessary?  By installing the Z-Card, did we eliminate some
programs that he might want to use someday?  Is it installed
properly? We did not try any slot other than slot 3. Is there
anything else that we should do to make his ][+ more useful?
    
                             Thanks,
    
                             Steve