[O] How to reduce width of section separators in agenda view?

[Richard Stanton]

I have an agenda view set up as an org-agenda-custom-command,

("H" "Office and Home Lists"
     ((agenda)
          (tags-todo "OFFICE")
          (tags-todo "HOME")
          (tags-todo "COMPUTER")))

This works fine, but I notice that each section of the agenda view is separated 
by a line of "=" signs 132 characters long, and when I print in portrait mode, 
these wrap onto the next line. How can I shorten these lines to only 80 
characters wide?

Thanks for any suggestions.

Richard Stanton