bind <key> scroll_backward

This executes the WINDOW SCROLL_BACKWARD command. It moves the scrollback view backward (towards older output). The amount it moves is determined by SET(4) SCROLLBACK_RATIO as a percentage. It is usual and customary when you scroll backward for the scrollback view to become the current view, so you should immediately see an effect.

EPIC will beep at you if you attempt to go further backward after you have already reached the start of the scrollback buffer.

When the scrollback view is active (after you use scroll_backward), new output to your window is buffered (held) without bounds, so you will never lose any output. But it will use more memory.