set xrange [1:8]
set title "Convex     November 1-7 1989"
set key below box
set label "(Weekend)" at 5,25 center
plot 'using.dat' using 3:4 title "Logged in" with impulses,\
     'using.dat' using 3:5 t "Load average" with points,\
     'using.dat' using 3:6 t "%CPU used" with lines