[address
]z
[type
] [count
]
Print a window of text, with the line specified by
address
at the top.
count
specifies the number of lines to be displayed.
Place specified line at top of window (the default).
Place specified line at bottom of window.
Place specified line in center of window.
Print the previous window.
Place specified line in center of window, and leave this line as the current line.