How to make vi redraw screen?

In Vi both of these are redraw:

• ^R ( does not work with VT100 type terminals )
• ^L ( does not work with Televideo terminals )

From http://www.cs.rit.edu/~cslab/vi.html#A1.4 (dead link; see archive)

As noted in the comments Vim now uses ^R for redo and ^L alone for redraw.

To force a screen refresh

:redraw!

If your terminal supports it, ctrl+L is a common shortcut for this.